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Full text of "73 Magazine (February 1997)"

Including Ham 




io Fun! 




FEBRUARY 1997 

ISSUE #437 

USA $3.95 

CANADA $4.95 



International Edition 



Software Home-brewing see page 10 




To Build: 



Beam-aimer 



Turbo Digi-sniffer 

Gel Cell Charger 

160m Antenna Tuner 

Stealth Antennas 



Reviews: 

Ten-Tec 6m Transverter 

Hamtronics RWX 



Photo by WQLMD 













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7^.85 7 I 


08725 -H 







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160-10 Meters PLUS 6 Meter Transceiver 



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*TT. *» Mm 

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t3JQj_ msoo 



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Fifteen reasons why your next HF 
transceiver should be a JST-245. . , 



1 



2 



3 



4 



5 



6 



7 



All-Mode Operation (SSB.CW.AM^FSK^M) on all HF amateur 
bands and 6 meters. JST-145. same as JST-245 but without 6 
meters and built-in antenna tuner. 

• JST-145 COMING SOON • 

MOSFET POWER AMPLIFIER • Final PA utilizes RF MOSFETs 
to achieve low distortion and high durability. Rated output is 10 
to 150 watts on all bands including 6 meters, 

AUTOMATIC ANTENNA TUNER • Auto tuner included as 
standard equipment. Tuner settings are automatically stored 

fn memory for fast QSY. 

MULTIPLE ANTENNA SELECTION • Three antenna connec- 
tions are user selectable from front panel. Antenna selection can 
be stored in memory, 

GENERAL COVERAGE RECEIVER • 100 kHz-30 MHz, plus 48- 
54 MHz receiver. Electronically tuned front-end filtering, quad* 
FET mixer and quadruple conversion system (triple conversion 
for FM) results in excellent dynamic range (>1 OOdB) and 3rd order 

ICP of +20dBm. 

IF BANDWIDTH FLEXIBILITY • Standard 2.4 kHz filter can be 
narrowed continuously to 800 Hz with variable Bandwidth Control 
(BWC). Narrow SSB and CW filters for 2nd and 3rd IF optional. 

QRM SUPPRESSION * Other interference rejection features 
include Passband Shift (PBS), dual noise blanker, 3-step RF atten- 
uation, IF notch filter, selectable AGC and all-mode squelch 



8 
9 

10 

11 



12 
13 
14 



15 



NOTCH TRACKING • Once tuned, the IF notch filter will track the 
offending heterodyne (±10 Khz) if the VFO frequency is changed. 

DDS PHASE LOCK LOOP SYSTEM « A single-crystal Direct 
Digital Synthesis system is utilized for very low phase noise. 

CW FEATURES * Full break-in operation, variable CW pitch, built 
in electronic keyer up to 60 wpm, 

DUAL VFOs ■ Two separate VFOs for split-frequency operation. 
Memory registers store most recent VFO frequency, mode, band- 
width and other important parameters for each band. 

200 MEMORIES * Memory capacity of 200 channels, each of 
which store frequency, mode, AGC and bandwidth. 

COMPUTER INTERFACE • Built-in RS-232C interface for 
advanced computer applications. 

ERGONOMIC LAYOUT • Front panel features easy to read color 
LCD display and thoughtful placement of controls for ease of oper- 
ation, 

HEAVY-DUTY POWER SUPPLY • Built-in switching power 
supply with "silent" cooling system designed for continuous 
transmission at maxim im output. 




flopon Radio Co., lid. 



430 Park Ave, 2nd Floor New York, NY 10022 Phone; (212) 355-1180 Fax: (212) 319-5227 

CIRCLE 159 ON READER SERVICE CARD 



Have Beam, Will Travel! 

Shake, nvist — your walking stick becomes a beam! 



How would you like a 
four element 2 meter yagi 
lhai travels the mountain 
trails as as walking stick? 
Pick a rest stop, remove the 
end cap, shake out the ele- 
merits and feedline. and in 
two minutes your HT is full 
quieting wherever you point 
it. 

Finished resting? Un- 
screw the elements and drop 
them into the boom; you're 
ready tor travel. But whenev- 
er you get the urge, iVs there, 
ready to zero in on a jammer, 
chase a radio fox, or shoot 
your signal out of a hole in 
time of difficulty. 

What is it? ArrowBeam. 
It shoots straight and true, 
and its strong flexible ele- 
ments are stored in the boom 
like arrows in a quiver. It 
weights only a pound and a 
half and is balanced in the 
hand, but it can tatie abuse, 

Keep it in the trunk of the 
car. It's tough exterior pro- 
tects everything against dam- 
age as it gets tossed and 
knocked about. But when it's 
time for action — shake, twist, 



and AirowBeam is ready to 
shoot your RF right where 
you want it. 

This handy versatile an* 
tenna is made to be dropped, 
bumped, and stepped on 
while you are racing through 
brush and branches in pursuit 
of the elusive radio fox* 
Drop it? It bounces. Snag a 
low limb as you drive by? 
Twang! the tempered ele- 
ments just spring back into 
position. Sit on it? You'll 
need a bandaid for your fan- 
ny, but ArrowBeam will be 
ready for more. 

Of course ArrowBeam 
will do just fine in an attic or 
on a mast even though its 
made for the torture of the T- 
hunt. 

Performance? ArrowBeam 
scored best for its boom 
length at the Dayton VHF 
competition. It's the antenna 
chosed by the FAA for its 
spook beacon and rogue ELT 
search teams. 

Now you can have Ar- 
rowBeam's performance and 
toughness for your radio ad- 
ventures. 





Half-Size ArrowBeam? 

Now there's a version of Ar- 
rowBeam that breaks down 
to half the Walking Stick 
size — the Grab-N-Go Arrow 
Beam, For storage the boom 
separates at the center, so 
the whole antenna stores in 
half the length — perfect for 
slipping in a backpack. 

You get the same great 
performance* the same ease 
of assembly, the same robust 
durability, but Grab-N-Go 
fits in your suitcase, 

The Grab-N-Go Arrow- 
Beam comes in its own for- 
est green stuff sack. There *s 
extra room there for other 
goodies you may wish to 
carry with your beam — 
feedline, homebrew PVC 
mast, omnidirectional Pico-J 
antenna, etc. This is the ver- 
sion Becca is taking on her 
trip, 

r 



ArrowBeams 

• Walking Stick 2m $79 

Elements 4 Boom Length 48" 
Gain 6. 1 dB Front/Back 10. 1 dB 
SWR <1 .1 min, <L5 band edges 

Add$6S&H 

• Grab-N-Go 2m $89 
Same as above, but breaks down 
to <25" for storage. Mast mount 
and Forest Green Stuff Sack in- 
cluded. Add $6 S&H 

• Walking Stick 70cm $49 
Elements 5 Boom Length 40" 
Gain 73 dB Front/Back 12.1 dB 
SWR <L1 min,<1.5 band edges 

Add $5 S&H 

Other Range Extenders 

•Pico-J 2m S19.95ppd 

• Pico- J 2m/70cm $26 ppd 

• 2m Packet Pico-J $22 ppd 

• TigerTail <2m/70cm) S8 ppd 



Save $5 



Order more than one item and 
knock $5 and shipping off the 
price of each after the first. 



i 



□ 



Yes. Send ArrowBeam 
Yes. Send my □ Pico-J 



: UWS2m OWSTOcm DGnGlral 
Modek . nTigerTail 



I 
I 



Name, 
Call 



Phone 



Street. 
City, 



Apt. 



State 



Zip. 



AntennasWeSt infofak Order Hotline 

Box 50062-5 Provo UT 84605 S 1 S(X) 926 7373 



I 
I 

I 

J 



CIRCLE 57 ON READER SERVICE CARD 



— ». 



i£ 



ASTRON 



COR 



9 Autry 

Irvine, CA 92718 
ION (714) 458-7277 * FAX (714) 458-0826 



NEW 



SWITCHING POWER SUPPLIES 

CONT. ICS WT.(LBS) 
SS-25 20 25 4.2 

SS-30 25 30 5.0 




J- 



ASTRON POWER SUPPLIES 

HEAVY DUTY • HIGH QUALITY * RUBBED • RELIABLE 



SPECIAL FEATURES 

• SOLID STATE ELECTRONICALLY REGULATED 

• FOLD-BACK CURRENT LIMITING Protects Power Supply 
from excessive current & continuous shorted output 

• CROWBAR OVER VOLTAGE PROTECTION on all Models 
except RS-3A. HS-4A, RS-5A, AS-4L RS-5L 

• MAINTAIN REGULATION & LOW RIPPLE at low line input 
Voltage 

• HEAVY DUTY HEAT SINK • CHASSIS MOUNT FUSE 

• THREE CONDUCTOR POWER CORD except for RS-3A 

• ONE YEAR WARRANTY • MADE IN u\SA 



PERFORMANCE SPECIFICATIONS 

• INPUT VOLTAGE; 105-125 VAC 

• OUTPUT VOLTAGE: 13.8 VOC + 0.05 volts 
(Internally Adjustable: 11-15 VOC) 

• RIPPLE Less than 5mv peak to peak (full load & 
low I i ne) 

• All units available in 220 VAC input voltage 
(except for SL-11A) 



SLSE 




RS-L SERIES 




■ LOW PROFILE POWER SUPPLY 



MODEL 

SL-11A 
SLUR 
SL-11S 
SL-11R-RA 



Colors 

Gray Black 



Continuous 
Duty (Amps) 

7 
7 
7 
7 



ICS* 

(Amps) 

11 
11 
11 
11 



Size (IN) 
H*W*B 

2% * 7 s * * W 
2%x7 *9*A 
2% x 7^ x 9 3 / 4 

m*7 x9^ 



Shipping 

WLllbsj 



12 
12 
12 
13 



POWER SUPPLIES WITH BUILT IN CIGARETTE LIGHTER RECEPTACLE 

Continuous ICS* Size (INI 

MODEL Duty [Amps) (Amps) H*W*D 

RS-4L 3 4 3Y2 x 6Ya * 7V< 

fis-5L 4 5 m*m*M 



as 



€ 
7 



RM SERIES 




MODEL RM-35M 



19" RACK MOUNT POWER SUPPLIES 

Continuous 
MODEL 

RM-12A 

RM-35A 

RM-50A 

RM-60A 

Separate Volt and Amp Meters 

RM-12M 9 

RM-35M 25 

RM-50M 37 

RM-6QM 50 



Duty (Amps) 
9 

25 
37 
50 



ICS* 
(Amps) 

12 

35 

50 

55 

12 
35 
50 

55 



Size (IN) 

HxWxD 

5^x19x8% 

5% x 19 x 12V? 

5%x19x12Y? 

7 x 19 x Wi 

5V4x19x8V4 
5V,x19x12V? 
5^ x 19 x12 V? 

7 x 19 x 12% 



*WL 



WL 



16 
38 
50 
50 

16 
38 
SO 
60 



RS-A SERIES 




MODEL RS-7A 



MODEL 

RS-3A 
RS-4A 
RS-5A 
RS-7A 

RS-10A 
RS-12A 
RS-12B 
RS-20A 
RS-35A 

RS-50A 

RS-70A 



Colors 
Gray Black 



Continuous 

Duly (Amps) 

2.5 

3 

4 

5 
7,5 

9 

9 

16 

25 

37 
57 



ICS* 

[Alttpl] 

3 

4 

5 

7 

10 

12 

12 

20 

35 

50 
70 



Size [IN| 

HxWxD 

3 x 4=% x 5V* 

3 3 /* X 6V* x 9 

3Va X 6Vjj X Vk 

3% X m x 9 

4x7 1 / 2 X 10% 

4^ x B x 9 
4x7Y* x 10% 

5 x 9 x 10V* 
5 x 11 x 11 

6 x 13% x 11 

6 x 13% x 12% 



Shipping 
WL |lb$.) 

4 

5 

7 

9 

11 

13 

13 

18 

27 

46 

48 



RS-M SERIES 




MODEL RS-35M 



MODEL 

Switchable volt and Amp meter 
RS-12M 

Separate volt and Amp meters 

RS-20M 

RS-35JVI 

RS-50W 

RS-70M 



Continuous 
Duly (Amps) 



16 
25 
37 
57 



ICS' 
(Amps) 

12 

20 

35 

50 
70 



Size | IN) 
HxWxD 

4V* x 8 x 9 

5x9x Wh 

5x 11 X11 

6x13 3 /< X11 

6 x 13 3 /* x 121k 



Shipping 
WL |lbi»] 

13 

H 

27 

46 
48 



VS-M AND VRM-M SERIES 




MODEL VS-35M 



RS-S SERIES 




MODEL RS-12S 



Separate Volt and Amp Meters * Output Voltage adjustable from 2-15 volts • Current limit adjustable from 1.5 amps 
to Full Load 

CiltfMilt 
MODEL Dltj (Amps) 

©13.BVDC @10VDC @5VDC 



VS-12M 
VS-20M 
VS-35M 
VS-50M 
VS-70M 



9 
16 
25 

37 
67 



Variable rack mount power supplies 
VKM-35M 25 

VRM-50M 37 



5 

9 

15 

22 

34 

15 

22 



2 

4 

7 

10 
16 

7 

10 



ICS 4 
|Ambs| 

@i3 + ev 

12 

20 

35 

50 
70 

35 
50 



Sizi [IN] 
H x W x D 



Shipping 
Wl. jibs.] 



4Vi X G X 9 
5 X 9 X IQtti 
5X 11 x 11 

6X 13 3 /i x11 
6x13^x12!i 

5 1 A X 19 X 12^ 
5 1 AX19X12V2 



13 
20 
29 
45 
4a 

38 
50 



Built in speaker 

MODEL 

RS-7S 

RS-10S 

RS-12S 

RS-203 

SL-11S 



Colors 

Gray Black 



* 



i 
* 
* 



Cottiftiois 
Ditf (Amps) 

5 

7.5 

9 

16 

7 



ICS* 

Anp* 
7 
10 
12 
20 

11 



Slzi (IN) 

H xW x D 

4 x 7^ x 10^4 

4 x Vk x 10^4 

AV% x 8 x 9 

5 x 9 x Wh 

2Va x 7% x 9 3 /« 



Shipping 

WL (lbt.| 

10 
12 
13 
18 

12 



ICS— Intermittent Communication Service (50% Outy Cycle 5min. on 5 mm. off) 



CIRCLE 16 ON READER SERVICE CARD 



THE TEAM 

Founder 

Wayne Green W2NSD/1 

Associate Pub Us her 
F. I. Marion 

Associate Technical Editor 
Larry Antonuk WB9RRT 

Nitty Gritty Stuff 
PrlscHla Gauvin 
Joyce SawteJIe 
David Underwood 

Contributing Culprits 
Bill Brown WB6ELK 
Mike Bryce WB8VGE 
Joseph J. Carr K41PV 
Michael GeierKBlUM 
JrmGray W1XU/7 
Chuck Houghton WB6IGP 
Dr. Marc Leavey WA3AJR 
Andy MacAllister WA5ZIB 
Dave Miller NZ9E 
Joe Moell KGOV 
Carole Perry WB2MGP 

Advertising Sales 

Frances Hyvarinen 
Roger Smith 
603-924-0058 
800-274-7373 
Fax; 603-924^8613 

Circulation 

Linda Coughlan 
Helen Senechai 

Data Entry & Other Stuff 

Christine Aubert 
Norman Marion 

Business Office 

Editorial ■ Advertising - Circulation 

Feedback - Product Reviews 

73 Amateur Radio Today Magazine 

70 Route 202N 

Peterborough NH 03458-1107 

603-924-0058 

Fax:603-924-8613 

Reprints: S3 per article 
Back issues: $5 each 

Printed in the USA by 
Quad Graphics 



Manuscripts: Co ntri but io ns for 
possible publication are most 
welcome. We'll do the best we can to 
return anything you request but we 
assume no responsfoility for toss 
or damage Payment for submitted 
articles wi be made upon publication 
Please submit both a olsk and a hard 
copy of your article (IBM (ok) or Mac 
(preferred) formats), carefully 
checked drawings and schemaocs 
and Hie dearest, best focused and 
lighted photos you can manage. How 
to write for 73" guidelines are available 
on request, US citizens must inciude 
their Social Security number with 
submitted manuscripts so we can 
submit it to you know who, 



10 
17 
21 
23 
26 
30 

32 



41 
70 
71 

75 



34 



44 




FEBRUARY 1997 
ISSUE #437 



Including Ham Radio Fun! 

Amateur 
Radio Today 

TABLE OF CONTENTS 



FEATURES 



Amateur Radio and Linux - W9?F 

Software home-br&wtng is hem! 

Elegant Rotating - Revisrted - W6ZZB 

An enhanced beam^aiming arcutt. 

Antenna Tuners - W6Y9T 

Do we realty need them? 

The Topbander * WBJ4D 

A cheap and easy antenna tuner for T6Q meters. 

Build the Turbo Dig [-Sniffer -AH 2HR/5 

A simpte-to-make digital Retd-strength metet 

Sumas Mountain High - VE76LD 

Building a self-sufficient repeater tower on a British 

Columbia mountain. 
Add a Microphone Preamplifier to Your 1 Meter Rig - AD5X 
Low<ost speech processing can increase your power. 
The Telegraph - K8KWD 
A tiffle device that changed Jne world 
The Get Cell Storage Battery - KB42GC 
A great tittle power supply 
In Search of Higher Power - WGYBT 
...and a safe connection for it. 
Antenna? What Antenna? - KB4ZGC 
A stealth antenna farm for a small lot. 
Hentenna Footnotes - AD1 B 
Using an EZNEC model to build a sample. 



WB64GP 



KB1UM 



K4IPV 



47 

88 

51 

48 

56 

6 

4 

84 

WtXU 87 

WB8VGE 61 

8 

58.88 



NZ9E 

WA5ZIB 

K0OV 

W2NSIV1 



DEPARTMENTS 

34 1 996 Annual Index 

58 Above & Beyond 
73 Ad index 

54 AskKaboom 

Barter + n* Buy 

Carr's Comer 

Ham Help 

Ham to Ham 

Hamsats 

Homing In 

Letters 

Never Say Die 

New Products 

Propagation 

QRP 

GRX 

Radio Book Shop 



WA3AJR 46 RTTYLoop 

62 Special Events 
83 Updates 



REVIEWS 



HAM RADIO FUN SECTION 



Hamtronics RWX Storm Watch Weather Broadcast Receiver 
- WA3WGV 

Hams need to know about storm emefgendes. 

The Ten-Tec T-K ft 6 Meter Transverter - NOB LX 
Here's a fine introduction to modem kft-butkJing. 



K20AW 64 Communications Simplified. 

Part 14 

WUDL 67 Simple T-R Circuit 



80 The Quest for the Ideal QTH 



On the cover: Photo by Bob Sliding WDLMD, who explains: The picture is my 2 el 40 beam, 
my 3 el 30 f 17, & 12 beam and my 2 & 3/4 beams for OSCAR @ 8,950 feet, Distant mountains 
are 15 miles away @ 14,000 feet." 



Feedback: Any circuit works better with feedback, so please take the time to report on 
how much you like, hate, or don't care one way or the other about the articles and 
columns in this issue. G = great!, O - okay, and U = ugh t The G's and O h s will be 
continued. Enough U's and it's Silent Keysviile. Hey, this is your communications 
medium, so don't just sit there scratching your. ..er... head, FYI: Feedback "number" is 
usually the page number on which the article or column starts. 



73 Amateur Radio Today (ISSN 1052-2522) is published monthly by 73 Magazine, 70 N202, Peterborough NH 
03458-1107. The entire contents ©1996 by 73 Magazine. No part of this publication may be reproduced without 
written permission of the publisher, which is not all thai difficult to get. The subscription rate is: one year 
$24.97, two years $44.97: Canada: one year $34,21. two years $57.75, including postage and 7% GST. Foreign 
postage: $19 surface. $42 airmail additional per year, payable in US funds on a US bank. Second class 
postage is paid at Peterborough, NH, and at additional mailing offices. Canadian second class mail registration 
#178101. Canadian GST registration #125393314. Microfilm edition: University Microfilm. Ann Arbor Ml 46106. 
POSTMASTER: Send address changes to 73 Amateur Radio Today T 70 N202, Peterborough NH 03458-1107. 
73 Amateur Radio Today is owned by Shabromat Way Ltd. of Hancock NH. 



Contract: See where natural ham curiosity gets you? Upon finishing reading the first sentence, you have 
formaily contracted with 73 Amateur Radio today to be our grass-roots ad salesman. You know we give you 
more ham fun for the buck than the rest— It should be a cinch to make this clear to dealers and manufacturers. 



Number t on your Feedback card 



Neuer srv die 



Wayne Green W2NSD/1 



■ 



"The Weather Here " 

When I hear those words I'm 
pretty sure the chap on the other 
end is going to be a dud contact. 
1 don't give a rat's rump what his 
weather is unless there's been a 
tornado or something really 
worth talking about. And 1 hon- 
estly don't care what commer- 
cial rig he was able ui afford, so 
none of that "The rig here Is*.." 
stuff either. That, too* tells me 
that he hasn't given any thought 
about what might be of interest 
to me, that I am just another for- 
mula contact For him. Gee, 
maybe he "needs" a NH QSL. 
Wowie, oh thrill I Thai's worth 
32g for me anytime, plus filling 
out the card and looking up his 
address in the CnHbook. Sure. 

When you call me 1 want to 
know something about you, not 
what kind of an antenna or what 
rig you bought. One of the rea- 
sons I wander off ham radio in 
my editorials is my obviously 
wasted effort to gel you to at 
least ask someone you're talking 
with if they've read my latest 
crazy editorial. And 1 recom- 
mend books which would give 
you endless things to talk about, 
if only I could get you to read 
them. Sigh. 

Yes, Til send you a con- 
founded QSL, Oh yes, and roger 
on your rig. your antenna, your 
weather, and the serial number 
on your mike. But are you active 
on packet, satellites, ihe 
Internet? Have you worked any 
interesting DX lately, maybe 
even been somewhere interest- 
ing? What do you think about 
the possible (maybe probable, 
considering the ARRL's undiplo- 
matic actions) loss of 2 meters? 
Talk to me! 

Boilerplate 

While 1 was at it I also put to- 
gether a collection of 43 of my 
ham-oriented editorials for ham 






club newsletter editors to use as 
filler when their club members 
fail to provide enough fodder. 
Those small filler items in news- 
papers are called boilerplate. 

1 get around 50 club newslet- 
ters every month and while some 
arc packed with interesting sto- 
ries, others are awfully dulk 
Since only about 20% of the 
hams read 73, it seemed to me 
that my editorials would be new 
for most newsletter readers, and 
could use some repetition for the 
others. And no snide remarks 
about my own repetition, please. 

Any newsletter editor inter- 
ested in getting some interesting 
filler can send me a copy of the 
newsletter and Til send a 
Boilerplate book. Yes, t can 
dump any desired segments to 
disk, if that* II help. Mac Word 
format. If you just have a morbid 
interest in my past ham-oriented 
edilorials the collection is $5. A 
steal 

Shocking 

A newspaper article from Gra- 
ham Rogers VK6RO cites an- 
other medical anomaly worth in- 
vestigating. This has to do with a 
chap who was suffering from 
Ross River vims, which pro- 
duces extreme fatigue and lasts a 
year or two. It*s transmitted by 
mosquitoes. It seems this chap 
who was suffering from the vi- 
rus had difficulty even getting 
out of bed. Then he accidentally 
goi pushed into an electric fence 
and got a dandy shock. The next 
day he had recovered from the 
virus. He told a good friend of 
his who also was suffering from 
the virus about it. The friend 
came around and zapped him- 
self on the fence and within 15 
minutes his pains were gone. 

Some lime ago 1 wroie about 
the Amazon Indian cure for 
snake bite where they take the 
wire off their outboard motor 
spark plug and zap the bile to 




counteract the venom. Indeed, 
the jungle aviation flyers lake 
along a spark coil system in their 
planes just for that emergency 

This lies right in with the let- 
ter from KA1UMW ("Letters") 
and his experiences. 

Now, I suppose you're going 
to ask me why the medical in- 
dustry is blind to these anoma- 
lies, How can they pass up re- 
searching electrical approaches 
to curing illnesses? You wouldn't 
ask that if you'd read the expose 
books on the industry on my rec- 
ommended list. The big money 
in the SL5 trillion American 
medical industry is in selling 
medications. If the drug compa- 
nies can't develop and patent a 
pharmaceutical which will bring 
in hundreds of millions, you 
aren't going to see it Or have 
you bought any pills lately? And 
the pill and shot pushers are sol- 
idly backed up by the AMA. the 
FDA, and on down the list, com- 
plete with swat teams to put you 
in prison if you try to cause any 
trouble, Lordy, you should see 
some of the letters I've been get- 
ting from FDA prisoners around 
the country! 

Perhaps you can understand 
why I'm so enthusiastic about 
the Beck blood purifier and 
Bioelectri Tier (May issue), 



Memorial 

What do you want to be re- 
membered for? If you ask a kid 
this he won't have an answer. It 
isn*t until you're along in your 
40s or so that you begin to 
understand what this means. 
We can't all leave great music or 
an behind as a memorial. Or 
even one stone in a great 
wall somewhere. So I sit here 
at my computer, listening to 
Gottschalk*s incredibly beautiful 
music, goading you to help pio- 
neer any of the endless frontiers 
of science which are wide open 
for exploration. Goading you to 



produce and raise the very best 
children you can. Goading you 
to help Fix our schools, our 
health care system, and all the 
oiher things you've let our be- 
loved Congress and president, 
solidly backed up by millions of 
bureaucrats, screw up. Will your 
memorial be a work of art? A 
book? A discovery? A lifetime 
score of 370 countries worked? 
Or perhaps a bunch of certifi- 
cates for winning contests which 
will eventually get thrown out 
with those old boxes of QSL 
cards by your widow? Or just a 
weathering stone in a cemetery 
somewhere? 

It doesn't take a Iol of 
money to pioneer. Mostly it 
takes determination, 

Speaking of bureaucrats, 
here's a quote I like: "A bureau- 
crat is the most despicable of 
men, though he is needed as vul- 
tures are needed, but one hardly 
admires vultures whom bureau- 
crats strangely resemble. I have 
yet to meet a bureaucrat who 
was not petty, dull, almost un- 
less, crafty, or stupid, an oppres- 
sor or a thief, a holder of a little 
authority in which he delights, 
as a boy delights in possessing a 
vicious dog. Who can trust such 
creatures?" Cicero* circa 50 BC. 
Who says we haven't made 
progress in 2,000 years? 

There's a whole world of 
mystery out there, waiting to be 
unraveled. Pick any thread and 
see where it takes you, 

Congratulations! 

Paul Harvey mentioned that 
our total taxes are now an aver- 
age of 50.4%" of our earnings, 
setting a new record. This is 
truly remarkable because in 
most other countries the people 
have revolted w hen the taxes got 
over 33%. So you are to be con- 
gratulated on your ability to get 
thoroughly screwed and yet 
keep on cheerfully smiling and 
re-electing your screwers. 

Yes, it's sure nice to have our 
social security payments when 
we get old. Of course, if the 
same money had been invested 
privately we'd be getting over 
three limes as much back. And 
the system wouldn't be looking 
at bankruptcy in a few more 
years. Sure, it's nice to have 
Medicare too. And never mind 
that if the government would let 
us invest our pre-tax earnings in 
health care insurance we'd gel 
much better care at less than a 
Continued on page 31 



A 73 Amateur Radio Today * February 1997 



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C3HCLE 34 ON READER SERVICE CARD 



Letters 



Number 6 on your Feedback card 



Mike Zaiw K6URI. Laic last 
year I wrote to you commenting on 
an editorial and mentioning our 
school ham radio club. Yon asked 
for information and photos. Here's 
the story. 

First 1 contacted all the high 
school, junior high and elemen- 
tary schools in our district to see 
if I could generate anv interest in 
starting ham radio cluhs. The 
three high schools, three junior 
highs and all hut one elementary' 
school were not interested. The 
only elementary school principal 
who was interested was one lhat 
my wile had taught for previ- 
ous! v. 



We started out in January 1992 
in a portable classroom that was 
being used as a library. 1 drxne my 
truck near the front door so we 
could use the mobile antenna with 
a portable rig set up in the room. 
This was not an ideal setup, but ai 
least we could make local contacts. 
This got some students interested. 
We now have a locked cabinet on 
the stage of the auditorium/ 
cafeteria, 

We meet only one day a week 
for one hour niter school. Some 
school terms 1 have eight lo 10 stu- 
dents, and sometimes only three in 
five. Our school district is so over- 
crowded thni the students are on a 
three-track system: on four months 
and off two months, Most of the 
kids do not come on their off-track 
time. 



From the Ham Shack 

It took almost four months for the 
administration i not the principal) to 
give their "permission" to start the 
club. The only requirements were 
these: The kids had to have a ride 
home after school (those who were 
bused); the club was at no cost to 
the district or school; and 1 couldn't 
electrocute any of the kids. So far, 
we have ntet all three requirements. 
Through equipment donations. 
mone\ for study books from our 
local adult city club, and my junk 
box. we have a pretty good setup. 
The station has an MFJ- 1270c 
TNC a Kenwood 10W TR-7600a. 
Kenwood TS-520s, Swan SWR/ 
wattmeter, and a 3S6DX-40 com- 
puter. On the roof of the auditorium 
we have a 2m antenna and a 20/40m 
trap dipole. 

Recently mv wife Kristv 
KE61QL got her Technician license 
and we decided to try to start an- 
other club at the elementary school 
where she teaches sixth grade. We 
got the principal to let us put a 
packet station in the classroom as 
a test. So, when she reLurns to 
school from off track, we will give 
it a go t 

Our club at Nichols Elementary 
si arts the kids out with some elec- 
tricity experiments and then they 
build it basic crystal radio. The next 
item is a Morse code key, followed 
by a two- transistor code oscillator. 
Then the crystal radio is converted 
to a one-transistor AM radio, and a 
small audio amplifier is added. IK 




Members ofK6URVs elementary school club working on their crystal 

radios. 

6 73 Amateur Radio Today 'February 1997 



the way. our club has students from 
grades four through six. Hopefully 
at the end of October, when my wife 
goes back on track, we will have 

another club gonii! and good news 
to report. I would like to be able to 
have the club members al both 
schools get on ATV, which might 
generate some more interest. 

Marry Goldman. Tesla Coil 
Builders Assn. Docs Bernard Finn 
have a problem? ("Letters." August 
19%.) Mention Nikola Tesla and he 
gives a list of also tans. I call it the 
"Oh but.. " syndrome. That is, you 
credit a person for his contributions 
to science and Finn comes up with 
the ,k Oh buis..." This game can be 
applied to anyone. Bell and the tele- 
phone, for example, as well as 
Edison for the incandescent lamp 
and the phonograph. It is no secret 
that there were others on their trail. 
And that's the crux of the arau- 
me nt— 4 hey were trailing and not 
leading. Surely Mr Finn is aware 
of the fact thai the Tesla polyphase 
patents were dragged through the 
cou its. Although the courts consid- 
ered the efforts of others, including 
those named by Finn, Tesla's pat- 
ents were upheld in every case. 
When Niagara went on line in 
1896, the famous Lord Kelvin 
declared that "Tesla had contrib- 
uted more to electrical science 
than any man up to his time." 
Whew, that Lakes in a bunch of 
highly respected names, 

1 agree with Mr. Finn lhat 
Edison's incandescent lamp estab- 
lished a need for a source of elec- 
tricity. But there were single-phase 
AC systems available at the lime. 
Why, then, did so many years pass 
between the birth o\' the incandes- 
cent lamp and Niagara hydroelec- 
tric power? It is no coincidence that 
Niagara hydroelectric came into 
existence shortly after the appear- 
ance of Testa's patents. 

Much o( the discussion above 
can be applied to the wireless te- 
legraphy controversy. By 1893 
Tfcsla had developed the principle 
of the four-circuit system of com- 
munications. The idea employed 
inductive coupling between the 
driving and working circuit, the 
importance of tuning both circuits, 
the idea of an oscillation trans- 
former, i he capacitance loaded open 
secondary, and tuned antenna cir- 
cuits grounded at one end Again. 1 






agree with Mr, Finn that there were 
others who later applied their own 
innovative ideas, But they would 
have gotten nowhere without em- 
ploying the above named comptv 
nents. The way to wireless 
telegraphy was through Tesla. 

Tcsla's contributions lo wireless 
telegraphy did not go unnoticed by 
hb peers. Tesla was hailed as the 
% Talher f of wireless telegraphy by 
L.W. Austin (leading US. Govern- 
ment radio expert), M.EL Giradeau 
(pioneer in French communica- 
tions), A, Slabv (whose work 
helped to establish the Telefunkcn 
system in Germany h A. Popov (of- 
ten referred to as the Russian 
Marconi)* as well as by others L 1 1 
Armstrong (FM and advanced ra- 
dio circuits j praised Tesla for his 
visionary work in wireless and 
credited Tesla as the originator of 
radio control systems. John S. Stone 
(named in the U.S. Supreme Coun 
decision) stated lhat "Tesla was so 
far ahead of his lime that the best 
of us mistook him for a dreamer." 

With numerous awards, 15 
honorary doctorates, a unit of 
measurement bearing his name, 
an IEEE annua] award presented 
in his honor, and so on. it is diffi- 
cult to understand why the 
Smithsonian can ignore Tcsla's 

accomplishments. 

The lack of artifacts is given as 
one reason. That situation did no! 
stop MGM when it was preparing 
for the 1940 film "Edison, the 
Man.'The studio sent ilsxmlismcn 
to museums with Edison holdings 
to take photographs and make mea- 
surements. It took only six weeks 
to replicate Edison's most impor- 
tant inventions, and that includes 
the Pearl Street generating station. 
These were not Hollywood props 
but 1 : 1 scale working models! Tesla 
artifacts are in abundance al the 
Tesla Museum in Belgrade. I am 
confident that the Smithsonian 
crafts department is just as capable 
as MGM's. 

Even if artifacts arc lacking, the 
Smithsonian has numerous papers 
on Tesla's work thai have been do- 
nated by engineers and historians. 
Why hasn't the Smithsonian used 
them to publish a monograph on 
Tesla? 

And in conclusion, I might as 
well mention my own personal 
complaint. In 1 994. a friend stated 
that he saw a portrait of Tesla at 



the Smithsonian. Thinking that it 
might be something I do not al- 
ready have, I sent a request for in- 
formation. Two years have passed 
without a satisfactory reply even 
though I have sent reminders on 
two subsequent occasions* 

The situation is a disgrace— 
another example of politics 
messing things up... Wayne. 

Raymond Bergeron KA1UMW, 

When I was less than 1 2, 1 saw a 
little German chiropractor (Dn 
Leonard A. Kaam) for relief from 
bronchitis symptoms, for an in- 
jury from a tree fall, and for 
Osgood Slatter's disease. This 
chiropractor had a "little black 
box" that ran on batteries, I would 
hold a solid brass probe in one 
hand while he probed the affected 
area with the other. He had a small 
figurine of the human body that 
was covered with numbers. When 
he wanted to treat my ailment or 
symptom (stuffed-up sinuses, for 
example), he would look up si- 
nuses in a book. The book would 
give him a list of numbers which 
he would find on the figurine. He 
said that the numbers were nerve 
ending points. Using his probe, he 
would touch the area of my body 
as indicated by the numbers. A 
tone would come from the box 
and get louder as he approached 
the nerve ending {presumably by 
finding the least resistance). 
When the tone was the highest in 
pitch he would push a button on 
the probe and a series of electric 
pulses would run through me 
(they would often be a little pain- 
ful) for about five seconds. After 
a few of these hits (around the 
nose for the sinus treatment), 1 
would feel the dams bursting and 
my sinuses would be instantly 
clear, with the gunk running down 
the back of my throat. He would 
always tell me that his box could 
cure anything, clear up a blocked 
artery, etc. He even said if I ever 
had a heart attack or a stroke, not 
to go to the hospital but to go see 
him and he would clear it up 
instantly, 

Well, he also had another gray 
box called a Century Mach IV 
Galvanic Stlmulizer. This little 
device had a big pad that was 
soaked in warm water and placed 
on your back, and two smaller wet 
pads that are placed on the injured 



area. The machine would run an 
AC current through your body. 
The current was variable from 
nothing to painful, at a frequency 
from 30 to 120 Hz, The current 
would switch from Pad A to Pad 
B, going to the big common pad 
on your back at a rate of 2.5, 5, or 
10 seconds. Well, as a late teen- 
and early 20-ager I started to ser- 
vice these little gray machines, 
which reportedly cost $5,000. My 
chiropractor managed to get a 
schematic for me so I could re- 
pair them. The unit was just a 
simple 36-volt pulsed variable- 
current generator, with a timer — 
sound familiar? 

If you have any chiropractor 
friends ask them about the phys- 
ics involved and it may help with 
the plant growth stimulator. 

Hmm t is this another lost tech- 
nology? Seems worthwhile inves- 
tigating . Were those " nerve 
endings'' actually acupuncture 
points? Maybe some of those 
fancy electrical gadgets of long 
ago which the "modern M medical 
industry ridicules actually did 
work! Of course, if your pioneer- 
ing spirit has been totally deci- 
mated, then never mind. And 
for heaven s sake don V read the 
Robert Becker books... Wayne. 

MikeTWiax KB90CE, Wayne, 
you recently asked to hear about 
Elmers, so I thought I would tell 
you about my Elmer: my brother 
Jerry Truax N3SEL 1 first became 
interested in amateur radio 22 years 
ago. My main interest then, as it is 
now, was HE I have an HW-9 that 
I built in the late eighties which has 
yet to go on the air. Every time I 
was ready to take the test, 1 either 
couldn't find the time and place of 
a test, or I was working. Finally, in 
June this year, after calling off from 
work, I took the test. I had origi- 
nally planned on going for Tech+ + 
However, when the YEs told me 
that 1 had only missed two on the 
entire exam, I was so excited that I 
knew I'd never be able to concen- 
trate on the code. 1 raced home to 
call my brother with the good news. 
His encouragement (and stubborn- 
ness) had finally paid off. A few 
days later I received a package from 
him. He had sent me a 2m HT so 
that I could get on she air as soon as 
my license arrived! There was one 
string attached. Now I have to 



become an Elmer, and the first one 
that 1 Elmer gets the HT upon pass- 
ing the exam... with the same string 
attached. That's a new twist on 
'Incentive licensing" for sure! 

I now have to study for the Gen- 
eral. 1 wish I had done this years 
ago. Most of the blame is my own; 
however, for the general public, VE 
exams are one of the best-kept se- 
crets around. I really think that our 
ranks would grow faster (and stron- 
ger) if more people knew about 
them. Our local Radio Shack™ 
knew nothing about local amateur 
radio activities, other than what I 
relayed to them. Most newspapers 
have a "community bulletin board" 
column. The newspapers can* t print 
dates for VE exams or local club 
meetings, etc., if they don't know 
about them. The best part is that this 
is free advertising! 

I suggest coverage of activities 
like Sky warn, Field Day, hamfests; 
the list goes on. I would really love 
to see an article about Bill 
KA90NS, one of our local ama- 
teurs who normally runs our 
Weathemet Bill and the guys do 
such a fantastic job, They too are 



part of the reason that 1 finally look 
time to get licensed. Hmmm, since 
1 am a free-lance writer, maybe Til 
write the article — after all, if we 
don't promote ourselves, nobody 
else will! Maybe our local club (and 
yours) could use a Publicity Chair- 
man. Volunteer! Remember the old 
saying: "Volunteers can't be 
bought; they 1 re priceless." It's true ! 
Don't worry, Wayne, I have a few 
articles in the works for you that I 
will be sending as soon as my re- 
search is complete. We could trade 
my work for back issues of 73. Af- 
ter all, they don't call you Never 
Spend a Dollar for nothing. 

I would like to thank not only my 
brother Jerry N3SEI, but also you, 
Wayne, for the encouragement 
through your editorials (yes, some- 
body was listening!), Gordon West 
for his excellent study materials, 
our local Sky warn Weathemet, and 
our local VEs— John KF9YS, Mike 
WT9W, and Stan KD9BE— for 
giving up their valuable time so that 
a 22-year dream could become re- 
ality. Each and every one of you is 
my Elmer in your own way, and you 
Continued on page 60 




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CIRCLE 226 ON READER SERVICE CARD 

73 Amateur Radio Today • February 1 997 7 



QnH . . . 



Number 8 on your F&edoack cgrtf 



Scholarships for Licensed 
Hams 

The Foundation for Amateur Radio, Inc., a non- 
profit organization with headquarters in Washing- 
ton D.C.. plans to administer 60 scholarships for 
the academic year 1997-1998 to assist licensed 
radio amateurs. The Foundation, composed of over 
75 local area amateur radio clubs, fully funds five 
of these scholarships with the income from grants 
and its annual Hamfest The remaining 55 are ad- 
ministered by the Foundation without cost to the 
various donors. 

Licensed radio amateurs may compete for these 
awards if they plan to pursue a full-time course of 
studies beyond high school and are enrolled in or 
have been accepted tor enrollment at an accred- 
ited university, college or technical school. The 
awards range from $500 to $2,500. with prefer- 
ence given in some cases to residents of specifted 
geographical areas or the pursuit of certain study 
programs. Clubs, especially those in Delaware, 
Flonda, Maine. Maryland. New Jersey, Ohio, Penn- 
sylvania, Texas, Virginia, and Wisconsin, are en- 
couraged to announce these opportunities at their 
meetings, in their club newsletters, during training 
classes, on their nets and on the World Wide Web 
home pages. 

Additional information and an application form 
may be requested by letter or QSL card, postmarked 
prior to April 30, 1 997. from: 

FAR Scholarships 

6903 Rhode island Avenue 

College Park MD 20740 

The Foundation for Amateur Radio, incorporated 
in the District of Columbia, is an exempt organiza- 
tion under Section 501(C)(3) of the Internal Rev- 
enue Code of 1954, It is devoted exclusively to 
promoting the Interests of amateur radio and those 
scientific, Nterary and educational pursuits that ad- 
vance the purposes of the Amateur Radio Service. 

73's "Survey" Winner 

The winner of $100 plus a lifetime subscription 
to 73 is Harry Longerich of Fredencksburg, "DC. 
Congratulations, Harry, and thank you for partici- 
pating in the "Survey" in 73 s November issue. 

Cities Will Challenge FCc" 

Look for major court challenges by city planners, 
community managers, and homeowners" associa- 
tions to recent rulings by the FCC— rulings that for- 
bid states, cities, municipalities, homeowners' 
associations, and even individual landlords from 
enacting rules preventing the installation of those 
pizza-sized satellite TV dishes. 

When it used its power and preempted local ju- 
risdiction and land use regulations to permit any- 
one to install one of the mini satellite antennas, the 
FCC said it was doing so to ensure that the general 

8 73 Amateur Radio Today * February 1997 



public had access to the latest in television trans- 
mission technology. 

But according to recent news reports, sane cities, 
states, and many homeowners' organizations dis- 
agree. A spokesman for a coalition of urban planning 
groups say that the federal government has no right 
to dictate the aesthetic look of a community; that con- 
trolling satellite dishes and any antenna structures 
must be done on a community planning level. 

With both sides now having their views cast in 
concrete, it will be up to the legal system to deckle 
who has the final word. Urban planners say ihat 
they will be going to court in an alf-or-notrnng effort 
to wrestle the power of federal preemption away 
from the FCC. While ft will be many years before 
any final determination is made, whatever the out- 
come, the future of many radio services that use 
visible antennas— including amateur radio— may 
well hang in the balance . 

Adapted from an editorial rn the imarcKey* 'official 
newsletter of the Manteca ARC, November 1996. 

Ham's Best Friend 

...like mans in general, is the dog. Why? 
10. He doesn't need a chair, 
9. He always answers your call. 
B* He entertains you when the bands are dead. 
7, He keeps your feet warm on cold winter 

nights. 
6. He never reminds you how late it is, 
5. He understands your frustration; he's been 

in a few dogfights himself, 
4. He doesn't talk while you're trying to copy 

code. 
3. He's one being whose CW skills are worse 

than yours, 
2> He doesn't care how much you spend on 

QRP gear. 
1 p He listens before he barks, 
By Steve Burel AD4LY (lifted from the "ARNS 
Bulletin," December 1996. which lifted it from the 
Colorado QRP Club's official newsletter, The Low 
Down. } 

FCC Enacts Morse Code 
Requirement on Internet 
Access 

(Note for the humor-impaired: This is satire. 
Please do not read this if you are not property trained 
and certified in satire.) 

The FCC T under pressure to clean up the Internet, 
especially after the Communications Decency Acl 
provisions regarding Internet content were stricken 
as violating the U. S. Constitution, has decided in- 
stead to enact a Morse code proficiency require* 
ment for internet users. Citing the success of the 
Amateur Radio Service and the general beiief that 
its requirement to operators to pass a Morse code 
proficiency exani + and other technical requirements, 
has kept the ARS "ctean," the FCC wilt enact a 5 
word-per-minute requirement for all Internet users. 
They are leaving open the issue o\ whether there 
should be a Modeless" class of Internet user and 



are soliciting comments for proposed rule making 
on this proposal, 

Persons wishing to develop a web site having 
only links to other web sites which in turn have only 
links to other web sites, and so forth, must pass a 
13 word-per-minute Morse code test and demon- 
strate proficiency in HTML, the Internet authoring 
language. 

Persons who wish to develop web sites that have 
actual content, as compared to just links to other 
web sites, must pass a 20 word*per*minute Morse 
proficiency test, demonstrate proficiency in HTML 
and the Java programming language, and show that 
they have mastery of at least one human language, 
such as English, 

The FCC, which lacks budgetary aulhority to 
implement the testing program, has stated that it 
intends to create a Volunteer Examiner Program to 
test internet applicants. 

Swiped in its entirety from Clear Lake ARC'S *Ra- 
die Amateur Gazette. ~ Octo be r i No vem be r 1 9 96 . 



Tucker Out of Ham Biz 

Tucker Electronics Company, a distributor of new 
and reconditioned electronic test and measurement 
equipment, amateur and shortwave radios, and elec- 
tronic hobbyist products, has announced the sale 
of all its ham radio-related assets (including the re- 
cently acquired Oklahoma Comm Center) to Ham 
Radio Outlet. 

Tucfcer Electronics has discontinued operations 
of its retail store in Dallas and its consumer mail- 
order business: the toll-free ordering number is be- 
ing serviced through HROs New Hampshire store. 
At last report. Tucker is marketing its vintage radios 
and any inventory not acquired by HRO on its web 
site (www,tucker.com). 

The sale of its amateur radio business will allow 
Tucker Electronics to focus on its core business, 
distributing new and reconditioned electronic test 
and measurement equipment. 



Nautical Smiles 



The following transcript of a radio conversation 
between a US Navy ship and a Canadian source off 
the coast of Newfoundland was released by the 
Chief of Naval Operations on Oct. 10: 

US Ship; Please divert your course 15 degrees 
to the north to avoid a collision. 

Canadian: Recommend you divert YOUR course 
1 5 degrees. 

US Ship: This is the captain of a US Navy ship. I 
say again, divert your course. 

Canadian: Mo, I say again, divert YOUR course. 

US Ship: This is an aircraft carrier of the US Navy 
We are a large warship. Divert your course now! 

Canadian: This is a lighthouse. Your calL. 

Reprinted from the newsletter of !he Escondido 
Amateur Radio Society, November 1996. who re- 
printed it from Ham Radio Online Internet magazine. 

Continued on page 53 





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Number Won your Feedback card 



Amateur Radio and Linux 



Software home-brewing is here! 



Richard Parry W9IF 
13842 Deergrass Court 
Poway CA 92064-2276 



October 5, 1991 : "Do you pine for 
the nice days of Minix-Ll. 
when men were men and wrote 

iheir own device drivers? Are you with- 
out a nice project and just dying to cut 
your teeth on m OS you can try to 
modify for your needs? Are you finding 
it frustrating when everything works on 
Minix? No more all-nighters to get a 
nifty program working? Then this post 
might be just for you/* 

With thai simple introduction, Linus 
Torvalds. a Finnish graduate student, an- 
nounced to the world Version 0.02 of 
Linux on the USENET newsgroup 
comp.os.minix. Linux is pronounced 



the kernel or core of the operating sys- 
tem; however in general it represents all 
the software that normally comes with 
a complete distribution. Platforms upon 
which Linux runs include: DEC Alpha, 
Commodore AMIGA, Sun Sparc. MIPS, 
Atari ST, and Apple Macintosh. How- 
ever, without a doubt, the 386, 486, and 
Pentium based systems are the most 
popular. Linux is not copyrighted and 
there is no AT&T code included (UNIX 
was born at AT&T). Linux is licensed 
under the Free Software Foundation's 
General Public License which specifies, 
amona other thintzs, that the source 
code must be freely available. It is the 



Who is it for? 

At the PACIFICON conference Bruce 
Parens AB6YM commented, 'There's a 
saying that marketing people have about 
programmers: 'Leave a programmer 
alone, and heMl come up with the kind of 
product that only a programmer could 
love," That's what UNIX is. and Linux 
too. Actually, other kinds of propeller- 
heads such as hardware designers, math- 
ematicians, etc, have been known to be 
comfortable with UNIX and Linux. But 
why use an operating system that only a 
nerd could love? Well, you want them to 
write more software, don't you? UNIX 
and Linux are the most comfortable 



a 



Where else but with Linux can you get the complete source code for a C++ compiler, an 
operating system, and the support of hundreds of thousands of users worldwide?" 



"Lean-nut ks based on the Finnish pro- 
nunciation of Linus. Linux is a perfect 
platform for software development for 
amateur radio. It offers a plethora of 
freely distributed high quality software 
and a knowledgeable and helpful com- 
munity of people (very much like the 
amateur radio community) ready, will- 
ing, and able to help; kind of like a 
ham's "Elmer." Although credit for the 
original idea for Linux must go to Linus 
Torvalds, the kernel and copious other 
software are the result of an international 
collaboration of dedicated people. 

No doubt the gamut of readers of this 
article range from those who use Linux 
on a daily basis at work and/or home to 
those who have never heard of it. For 
those who fall into the latter category, 
Linux is a 32-bit, mulli-tasking, multi- 
user, freely distributed UNIX-like oper- 
ating system. Technically, Linux is only 
10 73 Amateur Radio Today ■ February 1997 



inclusion of the source code that is per- 
haps most unique. If \ou ever wondered 
how an operating system, network, com- 
piler, assembler, or editor works, il is all 
there for you to study and modify to 
your heart's content. 

There was a time when most ham ra- 
dio operators built all or pari of their 
amateur radio stations. I have built my 
share of transmitters, electronic keyers, 
RTTY widgets, antennas and more. The 
desire to build was based on die thrill of 
learning and building. In fact, I remem- 
ber taking months to build a nifty gadget 
for the shack, using it for a week to see if 
it worked, and then returning to thinking 
of something else to build. I believe 
most of the amateur radio community 
feels the same wav. However, home- 
brewing now includes software, and for 
thai development Linux is the perfect 
platform. 



platforms for the development of sophis- 
ticated software that communicates, 
controls hardware, does complicated 
math ... what Km trying to say is that ii\s 
ihe best platform for developing the 
kinds of software that radio amateurs 
need." 

Who is Linux for? "Not for everyone" 
is the simple answer Linux and LWIX 
are industrial grade operating systems. 
They both support a wide variety of 
GUIs (Graphical User Interfaces), but 
they are predominately a CLI (Com- 
mand Line Interface), They are power- 
ful but with power and flexibility comes 
some complexity, Matt Welsh begins his 
book (see references) vuth. "Before you 
looms one of the most complex and ut- 
terly intimidating systems ever written: 
Linux, the free UNIX clone for the per- 
sonal computer, produced by a mish- 
mash team of UNIX gurus, hackers, and 



MT J HF/VHF SWR Analy 

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10 Ways to Tell if Linux is for You 



1 . You don't own DOS for DUMMIES. 



2. You don't hate typing. 



3- You don't mind reading manuals. 



4. You don't like going to bed before midnight. 



5. You don't own internet for idiots. 



6, You do like learning. 



7 T You do like challenges. 



8. You do like to build. 



9. You do like to experiment 



10. You can stop the VCR from blinking 12:00. 



Table 1. A humorous checklist to aid you in 
making the decision to use Linux* However, 
as with alt humor, there is always an element 
of truth. 

the occasional loon. The system iLself re- 
flects this complex heritage, and al- 
though the development of Linux may 
appear lo be a disorganized volunteer ef- 
fort, the system is powerful, fast, and 
free. It is a true 32-bit operating system 
solution/' 

If Matt's introduction has not scared 
you, then a more humorous test to see if 
you are ready for Linux is included in 
Table 1, Since you probably already 
have the hardware, a personal computer, 
and Linux is free, you have nothing to 
lose and a whole lot to gain. UNIX and 
Linux experience on a resume never hurt 
anyone! 

What's available? 

Just about everything you can imag- 
ine for serious software development 
is available for Linux. But that is only 
part of the story. The fact that it all 
comes with the source code and the 
enthusiastic support of authors and us- 
ers worldwide means you can probably 
get an answer to your question within 
hours, and that includes 3 a.m. Much 
of the documentation for Linux comes 
from the Linux Documentation Project 
(LDP) in the form of HOWTOs. These 
documents typically range from 10 to 
50 pages and provide in-depth infor- 
mation on a particular subject . There 
are currently 50+ HOWTOs to aid the 
user with Ethernet, XFree86, sound, 
video, networking, and more. For the 
amateur radio community, there are 
two in particular, a HAM and AX. 25 
HOWTO. Table 2 is based on the 
HAM HOWTO and includes a 
1 2 73 Amateur Radio Today • February 1 997 



summary of the software available for 
amateur radio. This document and 
other HOWTOs can be obtained from: 
http://sunsite.unc.edu/mdw/HOWTO 
and other mirror sites. 

However, the purpose of this article 
and of Linux is not to get you started 
assembling a computer system based 
completely on applications that you 
can download; it is to inform the ama- 
teur radio community of an operating 
system (OS) that is an experimenter's 
dream. Here is your chance to learn C, 
C++, Perl, awk, Smalltalk, Tcl/Tk, 
FORTRAN, Python, shell scripts, net- 
working, real-time systems, and more. 
It is a chance to put together a TCP/IP 
packet network that cannot be dupli- 
cated on any other platform. The rea- 
son for this is that the packet radio 
protocol is now built right into the ker- 
nel. Linux is the only operating system 
in the world that can boast standard 
and native support for amateur radio 
protocols. In fact, packet radio uses 
the same interface as the Internet. 
Therefore, any program which you use 
on the Internet can also be used as a 
packet radio program. For example, 
your favorite Internet programs such 
as Netscape, Mosaic, telnet, and ftp 
will work and not care, or know, that 
the medium they are using is packet 
radio. 

Getting started 

Table 3 shows the hardware for a 
comfortable system upon which to in- 
stall Linux. I want to emphasize the 
word "comfortable," since you can get 
away with a lot less, especially hard 
drive space. However, most of you are 
not going to give up DOS or Windows 
3.x right away (this might eventually 
happen, however) so you will want to 
make a partition on the hard disk for 
your DOS environment and another 
for Linux. One of the great benefits of 
Linux is that you don't have to give up 
anything you currently use. If you fear 
that Linux means leaving your current 
OS behind, fear not, Linux offers emu- 
lations for DOS, SVR3 UNIX, SVR4 
UNIX, Macintosh and even older com- 
puters such as the Apple II and Com- 
modore 64, For those of you who like 
GUIs, Linux has manv to choose from. 
There are several versions of X 
Windows, including: twm, fvwm, and 



Packet Radio 




JIMOS 




TNOS 




N0ARY Packet BBS for UN*X 




LBBS - Linux BBS message 
gateway 




MBL/RLI message to NNTP 
and E-mail converter 




Packet Cluster Node software 




Single floppy disk AX.25 router 




DPTNT Terminal & BBS 
package 




IPIP encapsulation daemon 




AXIP encapsulation daemon 




Ping-Pong Convers Server 




RSPF Daemon 




Michael Westfall's TTYLINK 
Daemon 




Craig Small's TTYLINK 
Daemon 


Morse Code 




GW4PTS Morse Trainer 




morse {aka superiormorse) 


AMTOR Software 


FACTOR Software 


Slow-Scan Television Software 


Facsimilie Software 


Design and Construction 
Software 




Software oscilloscope 




Printed circuit board design 
tool 




Chipmunk circuit design and 
simulation tool 




irism 




Spice vers. 3f4 




svgafft - Spectrum Analyser 




Audio Spectrum Analyser 




ObjectProDSP 


Training/Educational Software 


Miscellaneous Software 




Linux for HAMS CD-ROM 




SunClock 




Xearth 



Table 2. Partial list of amateur radio Linux 
software taken from the HAM HOWTO 
documentation written by Terry Dawson 
VK2KTJ. The entire HOWTO is available at: 
httpj! sun site Mnc .edu/mdw/HO WTO/ HAM- 
HOWTO. htm I. 



r 



386 machine or better. 



8 MB RAM (more is better). 



20 MB hard drive (SCSI, 
IDE, etc,)- 



Floppy drive (L44 MB high 
density). 



CD-ROM (any speed, SCSI, 
IDE, etc.). 



Video card supported by 
Linux. 



Mouse (3 -button type 
preferred). 



Table 3. Linux runs on many platforms; how- 
ever, for most hams the platform of choice is 
the PC. Shown here is a good hardware 
configuration for Linux software development. 

others. X Windows is a very powerful in- 
terface which allows great configuration 
flexibility. 

Regarding file formats, as you sur- 
vey the various distributions you will 
come across the terms "a. out" and 
"ELF" (Executable and Linking For- 
mat). Both are binary formats, the 
former being used for many years but 
now falling into disuse due to the ad- 
vantages of ELR The Linux commu- 
nity supports both formats during the 
current transition period. All of the 
distributions listed in Table 4 support 
ELF. 

During the installation of Linux you 
will be asked questions about your 
system's hardware configuration, 
Chances are you are using standard 
port assignments and addresses and 
the installation will go smoothly, but 
you should have your documentation 
handy just in case. For example, you 
might need to know your serial and 
parallel ports' I/O memory locations, 
and the IRQ (interrupt) addresses for 
devices (e.g., serial ports, sound cards, 
SCSI ports, video card, etc.). If you 
are not sure, most of the scripts have a 
default value to suggest, and in most 
cases you can't go too far astray stick- 
ing to the defaults in lieu of firsthand 
knowledge. Unless you have done 



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Linux for Hams is a fillHe&iured Liaux system vitft special additions for Amateur Radio. 

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something strange with your hardware 
configuration, the defaults should 
work tine. 

Although I said thai everything for 
Linux is free and can be downloaded 
from the Internet, I would not advise 
thai for anyone, even a UNIX guru, A 
small Linux installation can consist of 
a thousand or more files easily con- 
suming 50+ MB of space. A complete 
Installation which includes source 
code, copious documentation, com- 
puter languages and examples, and the X 
Window system can easily lake up much 
more (e.g. 500+ MB). For this reason 
downloading is not practical. Fortunately, 
there are many CD-ROM publishers who 
include a complete distribution of Linux 
along with excellent installation software. 



There is a lot more lo Linux than the 
kernel. There are editors, compilers, 
linkers, assemblers, and utilities, to 
name a few items* In fact, in most dis- 
tributions you will get several of each. 
For example, I have at least six differ- 
ent editors, although I use only one 
(emacs). For this reason it is not un- 
usual for a distribution to consist of 
two or three CD-ROMs. In fact, Mall 
Welsh's book (see references) can be 
purchased separately or with a 5 CD- 
ROM Linux distribution. The prices for 
all of the distributions are reasonable 
and they arc well worth it. 

Another reason for using CD-ROMs 
is to take advantage of the "installation 
scripts" that accompany the distribu- 
tions, some of which provide a graphical 








1 






Fig. 2. A SatTrack window written by Manfred Bester DL5KR. 

14 73 Amateur Radio Today •February 1997 



user interface. These installation 
scripts will walk you through the in- 
stallation process, asking you ques- 
tions about your system, Don't worry 
that you will be shielded from know- 
ing exactly w hat is going on during the 
installation there will he plenty of 
time for you to explore Linux later. 

Another source For information is 
your local bookstore. Go to the com- 
puter section and chances arc you will 
be surprised at the number of books 
devoted to Linux. 1 counted over a 
dozen during a recent visit, and ihere 
are many more that can help you 
during installation, configuration, 
networking, and more. 

Last, and certainly not least, the 
World Wide Web is a great source of in- 
formation. I have included a list of key 
web sites to visit in the references. Of 
particular interest to amateur radio op- 
erators is Bruce Perens" Linux for Hams 
homepage, shown in Fig. 1. 

Figs- 2 and 3 illustrate two of the 
many other features of interest to ham 
radio operators. Fig- 2 shows one of 
ihe SatTrack windows written by 
Manfred Bester DL5KR. SatTrack is a 
satellite orbit prediction and real-time 
tracking program with X Window Sys- 
tem color graphics displays. Il has 
been written in the C language and 
runs on UNIX and Linux systems, us- 
ing only basic XI 1 and XII Toolkil 
functions for the graphics displays, 
The program not only displays in real- 
time where a number of satellites are, 
hut is also capable of controlling suit- 
able ground station equipment, like 






~ 



HfV 



Thu MAP ^mrnfaAM sftovn m grspNc 3: form IM fietv.^*i 
unM r»pret«rt tra*e to* tore* node (\rt) to 
atttkiatksn node (ngW) 



l<C51Vi*fiOl« 




r ., si DM I 



NSAUX-15 I 




l kcsgjzfm 

^—♦r NSALft-IE 






aurr 



Fig. 3* A MAP window from XNET y a 
network analyzer designed specifically to 
monitor AX25 packet radio network\ 



antennas or optical telescopes* radio 
communications hardware or other 
sensors. An autolrack mode can track 
any number of satellites and switches 
automatically between them as they 
rise and set. Predictions of passes of 
satellites over specified ground sta- 
tions can be run off, either interac- 
tively or in batch mode. The page is 
located at: hup://www,primenetxom/ 
-bester/bts.htmL 

Fig. 3 shows a window from XNET, 
written by Richard Parry W9IF. This is 
a network analyzer designed specifi- 
cally to monitor AX.25 packet radio 
networks. Il will collect and display 
network data, allowing the user to un- 
derstand network traffic and channel 
utilization. XNET was written in 



"Linux offers a chance to put 

together a TCP/IP packet 

network that cannot be duplicated 

on any other platform— the 

packet radio protocol is now 

built right into the kernel" 



Tcl/Tk and provides many features 
that are useful to both the casual 
packet user and the packet radio BBS 
sysop wishing to better understand the 
network. The XNET homepage is: 
http://www,q ualcomm.com/-rparry/ 
x.net.himl. 

Conclusion 

Almost every amateur radio operator 
has been asked, "What is amateur ra- 
dio?" There arc a variety of answers 
and none are incorrect. For me, ama- 
teur radio is the thrill and excitement 
of experimentation, with both software 
and hardware* 

If you need to write a letter, do 
your taxes or develop a spreadsheet, 
there are computer systems that do 
that, and do it very well They give 
you the power to be your best and 
concentrate on the task at hand. For 
software development, however, you 
can't beat Linux. Where else can you 
get the complete source code for a 
C++ compiler, an operating system, 
and the support of hundreds of 
thousands of users worldwide? 



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73 Amateur Radio Today • February 1997 15 



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Table 4. Shown here is a list of popular Linux distributions. Although you can download 
everything on these CD-ROMs for free from the Internet, using a CD-ROM for installation is 
preferred. The time saved is well worth the price. 



References: 

1. Bible, Steve, "Amateur Radio 
on the World Wide Web— Part 2," 
QST, July 1995, pp. 37-40. 

2. Kirch, Olaf, Linux Network 
Administrator's Guide, O'Reilly & 
Associates, 1995, ISBN 1-56592- 

087-2. 

3. Lantz, Brian, "Using Ham Ra- 
dios with Linux," Linux Journal, 
May 1995, pp. 26-39. 

4. The Linux Journal Staff, "Linux 
Distributions Compared/' Linux 

Journal, March 1996, pp. 24-65, 

5. Strobel, Stefan; Uhl, Thomas, 
Linux: Unleashing the Workstation 
in Your PC, Springer- Verlag, Berlin 
Heidelberg, Germany, 1994, ISBN 
0-387-58077-8, 

% Welsh, Matt, Linux Installation 
and Getting Started, Specialized 
Systems Consultants, Seattle WA, 
1994, ISBN 0-916151-77-8. 

7. Yggdrasil Computing, The 
Linux Bible, Yggdrasil Computing 
Incorporated, San Jose CA, 1995, 
ISBN 1-883601-10-X. 

8. Linux newsgroups: 

comp.os.linux 



comp. os 4 in ux, advocacy 

comp.os,linux,announce 

comp.os-linux.answers 

comp.os.linux.development 

comp.os.linux. development.apps 

comp.os.linux.development,system 

comp.os,linux,hardware 

comp.os.linux.m68k 

comp.os.linux.misc 

comp. os Jinux.net working 

comp.os.linux. setup 

comp.os.linux.x 

9* Linux general information web sites: 

http://sunsite.unc.edu/mdw/ 

linux.html 
http://www.redhat.com/lg/ 

gazette_toc.html 
http;// www.geog.ubcc a/ 

sparclinux,htrnl 

10. Linux and amateur radio web sites: 
hup://www,rahul.nei/perens/ 

LinuxForHams/ 
http://sunsite.unc.edu/mdw/ 

HOWTO/HAM- 

HOWTO.html 

http://www.Hams.com/perens/ 
HamRadio/ 
LinuxAndAmateurRadio.html 

http://www.inx,de/~wah!in/ 
http://hppoolO.rz, hu-berlin.de/ 

~h0187akk/ 
http://www.qualcomm.com/ 

~rparry/xnet,html 



Number 1 7 on your Feedback card 



Elegant Rotating — Revisited 



An enhanced beam-aiming circuit. 



Chet Garrison W6ZZB 

3544 E. Dayton Ave, 

Fresno CA 93726 



A year or so ago, I was browsing 
through older issues of 73 and 1 
came across an article titled "El- 
egant Rotating," by L. B. Cebic W4RNL 
(73, June 1984). His article dealt with an 
earlier beam-aiming circuit by K9AZG 
(73 f November 1982), and offered some 
interesting improvements. The circuit is 
used to control CDE and similar rotor 
control boxes so that by setting a single 
potentiometer you can sit back and wait 
while the beam is aimed at the desired 
setting and stops, automatically. 

I don't know why I ignored the article at 
that time, but when I read the article again 
I decided to build it for myself because my 
rotor was of the CDE variety. 

I put the circuit together using point- 
to-point wiring and perfboard, and it 
worked beautifully! Because it was ugly, 
I hid it in a cabinet with a nice-looking 
front panel before I began using it 

Since then my oldest son has become 
licensed (KC6JAI). He and my friend 
W6BJ1 asked me to build an aimer cir- 
cuit for each of them. One had a 
the other a "tail twister" rotor. 





if 
• 



*l»1Ll*»*"i 




Qd)pMHMWtlPfjtw»w^i^* ' I nlff » iu ia » ^p iiwn 




Photo A. One of the partially-completed 
beam-aimers* 



In the meantime I had obtained a com- 
puter-aided design (CAD) program so I 
set out to make a circuit board for the 
aimer, and it was successful. (It wasn't 
easy, but the results were very gratifying.) 

Before submitting this article to 73, 1 con- 
tacted W4RNL and asked for permission to 
use information, including circuit diagrams, 
from his article. He replied and said OK, but 
also suggested I include some sort of audible 
device to help sightless operators, hence the 
little circuit added to the power supply board. 
Rotating the beam in CW direction produces 
a tone of one frequency, while rotating in the 
other direction produces a different tone 
(more about this later). 

Fm very happy with the results and 
have since replaced the original effort with 
a newer, and much neater, circuit. With 
this circuit I can rotate my beam a full 360 
degrees, stopping anywhere I want. 

The circuit 

I don't feel that it is necessary to 
go into K4RNL's article all that much. 
1 refer anyone wanting to build this 



H7 RW 

rAV jW- 



i H-I2V 



2SK 1 R1 
TONAL C*. 



2SK 1 ftl R2 

DIRECTIONAL <^ jyy^ 

CONTROL 



& 




Photo B. The main aimer board and the 
separate power supply board. 

rotator control circuit who feels the need 
for some theoretical information to the 
article in the June 1984 issue of 73. 

Instead, I have only included K4RNL*s 
circuit diagram, Fig. 1. Please note the fol- 
lowing correction to his original circuit: 
The lop normally- closed contact of K 1 is 
not connected to the top normally-closed 
contact of K2. The upper moving con- 
tacts of both Kl and K2 are connected to 
terminal #2 (common). 



Dl 




Kl 



K2 







RZO 



■^W I 
R16 J, 




J 



+12V 














) 



7^ 

3 A 



A 
5 

6 
7 B 



5 



>R13 03_ 

V. .'-.■ 

R19 




D4 



Lt- 



K3 



2V 



TO BRAKE 
CONTACTS 

IN 

CM 

CONTROL 
BOX 



Fig. i. K4RNL f s original circuit diagram 



73 Amateur Radio Today • February 1997 17 




Fig, 2. K4RNL's power supply. 

Fig. 2 shows K4RNL's power supply; 
Fig. 3 shows the audio oscillator There 
are four important potentiometers in the 
aimer circuit: Rl, R7, R8 and R9; and 
two in the audio circuit: R24 and R25. 

Rl is the potentiometer used to con- 
trol the rotation of the rotor, while R7 
and R8 are used to adjust the rotor stop 
points when the rotor reaches the end of 
rotation. They are adjusted to turn off the 
aimer circuit when full clockwise or coun- 
terclockwise points have been reached, 

R9 is used to adjust the delay time of 
the brake circuit. This adjustment allows 
for instant to several seconds of delay 
before the brake is applied, This an impor- 
tant feature; it allows the 
beam to coast to a stop be- 
fore the brake is applied. A 
beam antenna, even a 
small one, can develop 
quite a lot of torque when 
stopped suddenly. 

R24 and R25 are used 
to adjust the tones of the 
alarm while the beam is 
turning in one direction 
or the other — one tone 
for one direction and an- 
other for the opposite di- 
rection. This is an 
adjunct for the vision- 
impaired operator but 
can be deleted if it's not 
needed or desired. 

The oscillator is plenty 
loud and, as in my case, a 
small speaker can be 
mounted inside the en- 
closure. A convenient 
spot is on the power sup- 
ply board adjacent to the 
speaker connections, The 
values I have chosen in 
the oscillator circuit de- 
veloped pleasant tones 
for me. 



Fig- 4 shows the automatic beam- 
aimer circuit board (at 100% of actual 
size), ready for use with photocopier 
transfer system. Fig. S is the component 
side of that same board, showing parts 
placement. Fig, 6 shows the power sup- 
ply board, and Fig. 7 shows the compo- 
nent side of the board and placement of 
the components. 

Photo A shows one of the partially 
completed beam-aimers. LEDs at the 
left and right upper corners indicate 
which direction the rotor is turning. At 
the lower left corner there will be a 
power switch and in the lower right cor- 
ner there will be an LED "Power On" 




Fig* 3. K4RNL r s audio oscillator. 

lamp. Photo B shows the main aimer 
board and the separate power supply 
hoard. Unfortunately, the power supply 
board is not the one with the oscillator, 
Photo C shows how I "stacked" the two 
boards in order to minimize the overall di- 
mensions of the final enclosure. The cur- 
rent PC board layout allows the power 
supply board to be stacked above the main 
board for better heat dissipation. 

Construction suggestions 

Assuming you have etched or pur- 
chased the circuit boards, check all 
traces to be sure there are no breaks 




Fig, 4, Automatic beam-aimer circuit hoard, solder side (shown at 100% of actual size). 



18 73 Amateur Radio Today * February 1997 



anywhere. Visual inspection may not be 
good enough so I suggest a continuity 
check using an ohmmeter. Assuming ev- 
erything is OK, you may start installing 
the components. 

I recommend completing the power 
supply hoard first and checking it care- 
fully Install a fuse holder and a fuse, the 
LED, the power switch and the AC cord. 
Plug the board into a source of AC and 
turn it on. 

There should be ±12 volts DC between 
"G" and the positive terminal, and ±12 
volts DC between "G" and the negative 
terminal, You can now check the oscillator 
by temporarily connecting a lead from the 
positive terminal first to the TF Lermj- 
nal, then to the 'tCW" terminal, adjusting 
the potentiometers for a pleasing tone. 
Turn off the power supply and continue 
with the project 

In regard to the main board, I suggest 
strongly that IC sockets be used in all cases 
because if you happen to get a bad IC, it isn't 
easy to remove the IC without destroying the 
circuit board I also suggest that these sockets, 
as well as the insulated jumpers, be installed 
fiist, then the rest of the components, with the 
relays installed last Jumpers J I through J9 
are simply insulated wire jumpers* Check 
all the parts to be sure they are the right size 
and/or polarity. 

When you have completed the installa- 
tion of all the parts, connect the two boards 
together, with "G, M "+" and "-" on the 
power supply board connected to similar 
points on the main board. Also connect 
XW" and "CCW" from the power supply 
board to similar points on the main board. 

Testing 

You are now ready to do some checking. 
First, connect a 500 ohm potentiometer to ter- 
minals #3 and #7, with the arm of the pot con- 
nected to terminal #1 , This will be your 4i rotor 
pot" for the following tests. TUm this pot folly 
clockwise. Also, connect a separate source of 
12 to 15 volts DC, positive to terminal #3 and 
negative to #7. 

Plug the aimer to a source of AC and 
turn it on. If the voltages are OK, proceed 
with the next test 

In the event the CCW LED is on, re- 
verse leads 3 and 7 on the rotor pot, then 
adjust R7 to turn off that lamp. 

Now turn Rl to about midpoint; the 
CCW LED should light up. Now turn the 
rotor pot slowly counterclockwise until 
the CCW LED goes out* Continue 



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73 Amateur Radio Today • February 1997 19 



turning the pot in the same direction and 
the clockwise LED should go on. 

Turn hoth pots fully counterclockwise 
and adjust R8 so that the aimer circuit 
turns off; the CCW LED will go off 
Now turn hoth pots fully clockwise and 
adjust R7 to turn the aimer circuit off 
and the CW LED will go off, too. Both 
of these adjustments will have 10 be re- 
pealed when you actually connect the 
aimer to your rotor control box, 

A special note regarding the brake cir- 
cuit: You must bring leads from terminals 
#4 and #8 to the inside of your control box 
and connect them to the "open" brake con- 
tacts of the direction control switch. In 
each of my cases 1 installed an eight-prong 
"Jones type" socket al the hack of the con- 
trol box, connecting all the numbered 
terminals lo like-numbered terminals, ex- 
cept #4 and #8. This is the easiest method 
of putting it all together, believe me! 

When you first rotate your new system, 
turn your beam lo each extreme and again 
adjust R7 and R8 in order to turn off the 
aimer circuit Also, adjust R9 for a few 
seconds of delay in order to allow the 
beam to coasl lo a stop. 

Instead of a normal pot al R 1 , a 1 2-posi- 

tion switch might be installed with 2,000 

ohm resistors between each contact, 1 tried 

this idea and was satisfied with the results. 

Now, instead of holding a switch while my 

beam turns I simply dial in the heading. 

and gel back lo operating! 

Continued on page 69 



3 



70 , TO , 3D 

EdJL m 



n 



'& o 





Fig. 5. Component side of [he circuit board, showing parrs placement (not to scale). 



A 73 gift 
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Photo C. / "stacked" the two boards in order to minimize the overall di- 
mensions of the final enclosure. 

20 73 Amateur Radio Today • February 1997 




Fig. 6. Power supply circuit board (actual si^e}. 



Number 21 <m your Feedback card 



Antenna Tuners 



Do we really need them? 





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Fig, J. Miniature plastic dielectric variable 
capacitors can be used in extremely compact 
QRP antenna tuners. The circuit shown in 
Fig. la is useful for fine-tuning antennas 
that are close to resonance. For a wider 
range of matching use Fig. lb* 



Robert W. Vreeland W6YBT 

45 Maywood Drive 

San Francisco CA 94127 



Many hams use antenna tuners 
that are larger than their QRP 
rigs. Is this really necessary? 
While most transceivers are designed to 
withstand a three-to-one mismatch, this 
doesn't mean that they should be oper- 
ated that way. I decided to find out what 
my MFJ-9020 would deliver to a purely 
resistive mismatch. It put out 3.3 watts 
into a 50 ohm load and 3.2 watts into 25 
ohms, Not bad! The output dropped to 
2,8 watts for 82 ohms, 2.6 watts for 100 
ohms and a paltry 2, 1 watts with a 135 
ohm load. Apparently the MFJ-9020 
prefers loads of 50 ohms or less. 

Fortunately, most portable anten- 
nas will have an impedance in this 
range* According to Terman a half- 
wave horizontal dipole must be hung 
at a height of more than l/7th of a 
wavelength in order to have an im- 
pedance greater than 50 ohms, 1 What 



a lucky break for 40 meter QRP 
fans! Can you hang a 40 meter di- 
pole higher than 20 feet when you 
are out in the boonies with only trees 
for supports? 

Circuits to try 

So far we have only talked about 
purely resistive loads. What about 
that nasty thing called reactance? 
Most antennas have it and it really 
should be tuned out, which can be 
done by carefully adjusting the an- 
tenna length (usually not practical). 
An easier way is to insert either a ca- 
pacitor or an inductor in series with 
the antenna to cancel its reactance. 
But how do you know whether you 
need a capacitor or an inductor? 
Usually you don't, The answer is to 
use the circuit shown in Fig, la. It is 
useful for fine-tuning antennas 
which are near resonance. At reso- 
nance, the inductive reactance is 
equal to the capacitive reactance and 
cancels it, leaving zero. At lower 
frequencies the circuit becomes a ca- 
pacitor and at higher frequencies it 
is an inductor. This is a practical cir- 
cuit. It can be made from a small 
plastic dielectric broadcast tuning 
capacitor (Calectro A 1-233) and a 
toroidal coil. It is great for canceling 
the reactance of antennas with a ra- 
diation resistance near 50 ohms, 
such as a quarter-wave or a half- 
wave dipole. The circuit is not, 
however, an impedance transformer. 

If we add just one more miniature 
365 pF variable, we can build an im- 
pedance-transforming T network (Fig. 
lb). It will give you a perfect match. 
This network is the smaller unit shown 




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73 Amateur Radio Today • February 1997 21 



at the top of Photo A, I used pin jacks 
instead of UHF connectors for the input 
and output. When used with my MFJ- 
9020 it matched 25, 50 or 100 ohms 
without any measurable loss. However, 
when I tried it with 18 watts and a 50 
ohm load, I lost a watt. Better stick with 
QRP or the plastic dielectric in the 
capacitors might melt! 

With my 27 wait MOSFET rig I 
use the circuit shown in Fig, 2. 1 The 
capacitors were borrowed from an 
MFJ tuner. Band changing is done 
with a jumper on a double banana 
plug. It grounds eilher the 20 or the 
40 meter coil. On 80, the 40 and 80 
meter coils are connected in series. 
To complete the unit, I added a 
VSWR meter using the directional 
coupler from a burned-out meter. 
The complete tuner measures only 
5-7/8" by 3-1/8" by 3", and weighs 
just 1.25 pounds. 

You may wonder why I chose tor- 
oidal coils rather than the higher Q 
air core ones commonly found in an- 
tenna tuners. Well, my home-brew 
tuner and the MFJ-900 both put out 
26 watts into a 50 ohm load. How- 
ever, for a 25 ohm or a 100 ohm 
load, the home-brew tuner was the 
winner by a watt or two. The toroi- 
dal cores are available from Amidon. 

Oh, one other thing. How come 
manufacturers persist in packaging 
their standing-wave meters in mas- 
sive plastic cases or even heavier 
steel ones? You can easily build your 
own and it will weigh less than half 
a pound. Two examples are shown at 
the bottom of Photo A, On the left is 
a toroidal transformer bridge {ARRL 
Amentia Book). 




Photo A. Very compact antenna tuners can 
be built using toroidal coils and miniature 
capacitors. The larger unit is used with my 
27 watt MOSFET amplifier. At the bottom 
are two types of standing-wave meters. 

22 73 Amateur Hadio Today * February 1997 




Fig. 2, This medium power antenna tuner 
utilizes air dielectric capacitors . A shorted 
double banana plug is inserted into jacks 
connecting coils for the desired band. 



This type of VSWR meter can be 
very compact. They are, however, a 
bit tricky lo build and adjust. Most 
commercial tuners use a three-wire 
shielded transmission line as a di- 
rectional coupler. Some use three 
silver-plated rods suspended in a 
metal trough. Others use three paral- 
lel traces on a circuit board. I built 
the one shown in Fig. 3 and Photos 
A and B using a 6-1/2" length of 
RG-58 A/U. First I removed the 
outer plastic jacket. I then opened up 
the braid a little bit. Next I threaded 
two lengths of #22 tinned bus wire 
into Teflon™ spaghetti. I then 
threaded the insulated wires inside 
the braid, trying to keep them on 
opposite sides of the center conduc- 
tor. The circuit is shown in Fig, 3. 
Be careful to keep the leads to the 
1N67A diodes and the 150 ohm 



OUT 




0,02 





,10K 




- (u 







02 


s 


L TT J 











50 vA 



Fig. 3. A simple standing-wave meter using 
an RG-58 AID directional coupler. The 
2200 ohm resistors are RF filters. They also 
help protect the meter against burnout at 
maxim um s e nsitivity. 




Photo B. A modified length of RG-58 A/U 
makes an ideal directional coupler, if care- 
fully constructed with shorr leads, no adjust- 
ment will he required for a perfect balance. 



resistors very short, as shown in 
Photo B. If you can't find 1N67A 
diodes, use 1N34A. The RG-58 
A/U braid should, of course, be 
grounded at both ends. I borrowed 
the calibrated meter from a dis- 
carded Radio Shack™ standing- 
wave meter. If carefully constructed, 
the result should be a perfectly bal- 
anced VSWR meter. It should need 
no adjustment. 

While not absolutely essential, an 
antenna tuner can be a useful addi- 
tion to any portable station, espe- 
cially when less than ideal antennas 
must be used. This does not mean, 
however, that the tuner must be a gi- 
gantic box. Careful construction can 
result in a handy compact tuner, and 
a lightweight standing-wave meter. 

References: 

1, Terman, RE., Radio Engineer's 
Handbook, McGraw-Hill, 1943 (curve, 
page 791). 

2. Vreeland, R + W^ "Transformerless 
Amplifier/' 73 Amateur Radio Today, 
August 1995, pages 48-54. 

Parts Sources; 

Calectro, GC Electronics Division 
of Hydrometals, Rockford, Illinois 
61101. 

Amidon Associates, 10233 Otsego 
St., North Hollywood CA 91607 



Toroid Winding Instructions (all cores from Amidon} 


Band 


QRP Tuner 
(Fig, 1b) 


Medium Power Timer 
(Fig, 2) 


BOm 


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l8T#20onT1u6-6Core 


40m 


18T#a0onT6a-6Cone 


19T #20 on T68-6 Core 


20m 


1 0T #20 on T50-6 Core 


10T #20 on T50-6 Core 



Number 23 an your Feedback card 



The Topbander 



A cheap and easy antenna tuner for 160 meters. 



With the current sunspot cycle 
seriously affecting operations 
on the high frequencies, the 
160 meter band presents some attractive 
wintertime operating alternatives. It is 
not plagued with QRM from foreign 
broadcast stations like 40 meters. The 
"top band" is not crowded like 75 meters 
and the operators arc more friendly and 
more accommodating than some of the 
groups on 75 meters. Some have called 
160 the "gentleman's band/* 

For many years I was under the im- 
pression thai successful operation on 
160 meters required long lengths of wire 
at high altitudes and miles of radiaK 
However, not many of us can erect a di- 
pole antenna that is 260 feet long — not 
many of us own the large area of land re- 
quired for an extensive radial system. 
The good news is that we can still gel in 
on the fun and action on 160 because 
none of this special stuff is essential on 
160 meters! Granted, if you want to 
work DX regularly on the top band you 
would be advised to erect large antenna 
systems with as much height as possible. 
You will want to experiment with spe- 
cial receiving antennas, and be sure to 
include the best radial and ground sys- 
tem possible, However, routine opera- 
tions such as rag-chewing and meeting 
your friends on 160 can be very reward- 
ing without going to extremes on the an- 
tenna and radial systems. In fact, you 
can have loads of fun on 160 with just a 
small amount of effort. 

The secret of my successful 160 op- 
eration, and the object of this article, is a 
home-brew antenna tuner which I call 
"The Topbander/* I have worked sta- 
tions over thousands of miles away with 
excellent results while running only 100 
watts of power into a 75 meter dipole. I 



Kenneth Lowrey W8ND 

7716 0ceoia Lane 

West Chester OH 45069 



even made a contact with a QRPer who 
was running only 10 watts on SSB ! QRP 
on 160? Yes, fun activities on 160 await 
sou. All you need is a length of wire (it 
does not have to be a dipole) and The 
Topbander. The Topbander described in 
this article can be assembled in just a 
few hours. An added benefit is that this 
project is very kind to the wallet! 

Construction 

This antenna tuner is different from 
any other that I have seen because it uses 
no variable capacitors. The capacitors 
are Fixed, and the inductance is variable. 
There are several reasons for not using 
variable capacitors. Variable capacitors 
for frequencies like 160 meters are large, 
difficult to find, and usually expensive. 
Large variable capacitors at these fre- 
quencies mean a lot of big plates, which 
require a lot of chassis space and take 
up a sizable part of the operating area 
as well. In addition, if you wish to oper- 
ate with high power, even wider plate 
spacing is required to eliminate arcing 
during transmissions; this compounds 
the size problem. Furthermore, a large 




F ig* L The schematic diagram of the tuner is 
a simple series circuit. 



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73 Amateur Radio Today * February 1 997 23 



antenna tuner looks out of place in 
today's high-tech, small-size-equipment 
operating environments. By using inex- 
pensive fixed value capacitors you can 
eliminate the high cost of variables and 
build a tuner which is capable of high 
power operation but is still small in size. 
My finished tuner is mounted on a piece 
of wood and measures only 6' 1 wide x 5" 
deep x 8" tall! 

Fig, 1 shows the schematic for the 
tuner. Talk about simplicity ! The compo- 
nents are a home-brew coil and a capaci- 
tor bank consisting of a series-parallel 
network. Start construction of the tuner 
by winding the coil 

My coil consisted of 40 turns of insu- 
lated wire, I used #14 solid copper wire, 
which is normally used for house wiring. 
The wire is close- wound, using the insu- 
lation as a spacer between turns. Yes, we 
have been told that power could be lost 
to the insulation due to coil heating, but 
this is more theoretical than actual; my 
coil shows no signs of running warm 
even after 30 seconds of kcydown at 800 
watts. 

This tuner is designed for a 75 meter 
dipole with a feedline shorter than 65 
feel in length, I have been operating on 
160 for some time now with nothing 
more than a 75 meter inverted vee which 
is about 45 feet high at the center. In 
fact, one end is only 12 feet off the 
ground and the other is only about 18 
feet high. The vee is a balanced antenna, 
fed with 450 ohm ladderline and works 
all bands from 80 to 10 meters. How- 
ever, for 160, I short the ends of the 
ladderline together in the shack and Teed 
the antenna as a longwire* If you have a 
coax-fed antenna, you can connect the 
center conductor and shield together and 
feed it as a long wire. If you use other 
than a 75 meter dipole, or your feedline 
is longer than 65 feet, you may need to 
tap your coil at different turns. In fact, 
you may have to change the tuner from a 
series arrangement (Fig. 1) to a parallel 
arrangement (Fig. 4) to get a low SWR. 
In either arrangement, the tuner is still 
very simple. 

My experience has shown that the tap 
settings may change as the weather 
changes. Now, do not run to tell your 
friends that you can predict the weather 
from reading coil taps! The reason that 
the coil settings change with the weather 
is that the 75 meter dipole antenna is 
electrically short at this frequency. With 
24 73 Amateur Radio Today • February 1997 



r$H> 



From Coil 



^BH 



To Antenna 



a^ 



^"3 



Fig. 2u The capacitor bank is a series-parallel 
network of 470 pF capacitors; total 
capacitance equals 940 pF. 

electrically short antennas, the higher 
the ground resistance, the more power is 
lost. Resistance in soil varies consider- 
ably due to changes in soil moisture and 
temperatures. As a result, variations in 
the soil conductivity around your ground 
system affect the number of coil turns 
needed for a resonant circuit at your lo- 
cation, and the placement of coil taps. 
So, even slight changes in ground resis- 
tance will affect the tuning circuit, such 
as after a rain or snowfall; the Lap posi- 
tions will also have to be changed as the 
soil dries during prolonged periods of 
drought. After a short period of operat- 
ing under different weather conditions, 
you will discover where your coil taps 
should be placed to obtain the lowest 
SWR. The SWR does not have to be 1:1 
to obtain power output. An SWR of 1.2 
or even 1.5 may result in full output on 
160, 

Making the coils 

To construct your coil, first cut an 8"- 
long piece of V schedule 40 PVC plastic 
pipe (note that T plastic pipe is the in- 
side diameter; your coil form will be 
about 2-3/8 " outside diameter). Then 
drill a small diameter hole about 1/2 " 
from each end. Insert a small screw into 
each hole and slip on an eye-type con- 
nector before tightening the connection 
with a nut. Solder a length of # 14 solid 
copper wire into one of the eye hooks. 
Next, wind the wire on the coil form, 
and solder the other end of the coil to the 
hook on to the other end of the coil form. 
The coil should be tight against the coil 
form, but it may not be as tight as a fac- 
tory-made coil, and a little "play" is ac- 
ceptable. ( found strips of duct tape to be 
useful in holding the coil in place during 
the winding and soldering process. 

Several taps will probably be required 
on your coil. I had to start my taps at five 



turns from the ground end, and at three 
turns from the output end. Cutting coil 
taps in the wire insulation is easy; the se- 
cret is to take your time and try not to cut 
or nick the wire. I used a hobby-type 
knife to remove the wire insulation for 
the taps, Make certain that your blade is 
sharp, and make your cuts very carefully. 
Most hobby knives are very sharp, and 
you can cut yourself easily. Remember 
that this is amateur radio, and safety is 
our first concern. 

Place the coil in a vise in a horizontal 
position, taking care not to crimp or 
damage the wire. Choose a coil tap point 
and make a vertical cut along one side of 
the wire, again trying not to cut or nick 
the wire. I made my tap cuts about 3/4' 1 
in length. At the top and bottom of your 
vertical cut make horizontal cuts across 
the insulation to expose the bare copper 
wire. It is advisable to "stagger" the taps 
so as not to interfere with adjacent tap 
points. I used small alligator clips to test 
the SWR, and when I found the tap posi- 
tions which gave me the lowest SWR, I 
connected permanent coil taps. To do 
this, I used pliers to curl the end of a ring 
or eye connector, placed it around the 
bare wire, then crimped and soldered the 
connector to the wire. Be careful not to 
solder to the adjacent coil turns. Once 
the placement for the permanent taps 
were determined, you can make a new 
coil by unrolling the old one and using 
it as a pattern to determine the tap 
locations on the new wire. This is eas- 
ily done if you place one end of both 







ff^^ mm *^^^ m ^>\ 


. Output 

= — p to Capacitors 


r " 








==SeS T=- = ^* ^ 
























/ input 

1 from Transmitter 









Fig. 3. Wiring the tuner is easy. Simply 
connect one alligator clip from the transmit- 
ter to rhe coil, and another clip from the coil 
to the capacitor bank. 



wires in a vice. You may decide, as I 
did, to use your prototype coil as your 
permanent one. This is OK too, if you 
did not nick the wire when removing the 
insulation. Remember that ground resis- 
tance changes with soil temperature and 
moisture content; make a number of 
QSOs over several weeks with your 
Topbander under different weather con- 
ditions so that you will know how many 
permanent taps you will need and where 
these taps should be placed on your coil. 
You may choose to purchase coil 
stock instead of winding your own coil. 
A good choice would be an 8 "-long coil 
with a 2-1/2" diameter, and six turns per 
inch. 

The capacitor network 

Next, build the capacitor network. 
Note that the capacitors are in a series- 
parallel network (Fig, 2). If you wish, 
you may substitute other capacitor val- 
ues in your series-parallel network. If 
your capacitor values are different, then 
the number of coil turns required for 
resonance will also change. The formula 
for calculating series and parallel ca- 
pacitance is found in all of the amateur 
handbooks and in most electronics text- 
books. However, if you use the same 
schematic as Fig* 2, and all of your ca- 
pacitors are of the same value, the total 
capacitance of your network will be 
twice the value of one capacitor in your 
bank. I used 470 pF capacitors and the 
total value in my bank of capacitors is 
940 pR Also, you do not need low toler- 
ance capacitors; 20% tolerance is fine. If 
you have precision-value capacitors in 
your junk box go ahead and use them if 
you like, but they are not required for the 
success of the project 

You will need high-voltage fixed- 
value capacitors for this tuner. I used 
3 kV capacitors in my circuit* My ca- 
pacitor bank will take 800 watts of 
power at keydown for over 30 seconds 
without heating. Mica transmitting ca- 
pacitors are probably the best choice for 
this application, but I used disc capaci- 
tors because that is what I had in my 
junk box. I used NPO disc ceramics to 
keep heat from affecting capacitance 
values, but NPOs are not required. 

If you do not have any high- voltage 
capacitors in your junk box, there are 
several sources for them. You could can- 
nibalize an older tube-type television 




Fig. 4* An alternative diagram for antenna 
systems withfeedtines longer than 65 feet. 

chassis. Another source would be the 
flea market vendors at hamfests. If these 
efforts are not successful, ask around on 
the 2 meter repeaters or at your club 
meetings; sometimes other hams have 
transmitting-type capacitors in their junk 
box just waiting to be used. A fourth al- 
ternative would be to purchase the re* 
quired capacitors from a retail vendor; 
they are usually not expensive. Some 
surplus dealers sell high-voltage trans- 
mitting capacitors. (Radio Shack™ 
stores generally do not stock high-volt- 
age capacitors.). If all else fails, send me 
an SASE and I will help you locate the 
necessary parts, 

I built my capacitor bank on a small 
piece of perforated board which mea- 
sured about 2-1/2" square. In order to 
save space, I mounted both the perfo- 
rated board holding the capacitor bank 
and the coil vertically on a piece of 
wood. 

The wiring 

The wiring of the tuner is very simple. 
Simply run a short piece of coax from 
the transceiver to the tuner and connect 
the center conductor to an alligator clip 
for the input coil tap (Fig, 1). Attach the 
coax shield and your earth ground to the 
low end of the coil. Then use another al- 
ligator clip for the other tap and connect 
it to the capacitor bank (Fig, 3), 

Connect the output from the capacitor 
bank to the antenna, and feed it as a 
longwire. If you have a feedline longer 
than 65 feet, connect the capacitor bank 
across the coil (Fig, 4). Adjust the taps 
for the lowest SWR and you are in busi- 
ness with The Topbander! 

If you want to do some very enjoyable 
hamming with low QRM during the 
wintertime, without huge antennas and 
without huge outlays of cash, then 160 
and The Topbander are for you. 




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73 Amateur Radio Today • February 1997 25 



Number 26 on your Feedback card 



Build the Turbo Digi-Sniffer 

A quick, cheap and easy digital field-strength meter. 



Dave Pelaez AH2AR/5 

7309 Centenary Dr. 

Rowlett TX 75088 



Whether you are involved in 
foxhunting, testing actual an- 
tenna performance or "sniff- 
ing out" leaky transmission lines, a sen- 
sitive field-strength meter (FSM) is an 
excellent addition to the ham shack. 

The heart of ihis digital FSM utilizes 
an already-assembled liquid crystal digi- 
tal display that has become available 
through numerous sources/distributors. I 
initially found one of these displays at 
the Dallas hamfesL Originally, the rea- 
son for buying the display was to use it 
in another application as a digital fre- 
quency readout for an amateur television 
downconverter. However, once I exam- 
ined the display, I immediately recog- 
nized its potential use as a digital FSM. I 
returned to the hamfest the following 
day to get the name of the distributor, 



and much to my disappointment, 
couldn't find the guy who had been sell- 
ing them — he must have packed up 
early. 

Several months later I was in the Day- 
ton, Ohio, area, and rediscovered an- 
other source for these displays: Midwest 
Surplus Electronics. I checked with the 
store owner and he verified that he had a 
reliable source for these displays, and 
Midwest Surplus also had all of the parts 
called for in this 'Turbo Digi-Sniffer" 
article. (See the toll-free number and 
address at the end of the Parts List.) 

The display 

Described as a 3-1/2-digit LCD panel 
meter, the display is manufactured in 
Korea. The model number is listed 



as "PM-128." The panel meter comes 
already assembled and uses a dual-slope 
integration analog-to-digital converter 
circuit. It has a sample rate of three read- 
ings every second. The maximum volt- 
age that can be measured with this 
display is 500 volts; this can be done by 
simply changing the value of two resis- 
tors. The display can be set up to read at 
the microvolt level so it can become the 
main building block for a digital 
field-strength meter. 

Construction: digital panel meter 
modifications 

The panel meter circuit board's silk- 
screened pads show a pair of pads 
marked "RA" and "RB" (see Photo B). 
The 1 megohm potentiometer that will 



OP AMP 
LM324 



1MEG 

OHM 

POT 



\7 



.01 MFD 1N34A 



P30 
P20 

Ann n n n n.n n n n n n r* n 




j( 7I06CPL 

• 9405 J BJ • 

HONG KONG 



PI 

Jumpered 



PM-128 LCD DISPLAY 



Fig. LSchetnaticfor the Turixj Digi-Sniffen When using this circuit with the WD display \ the display and ihis circuit must have separate 9 volt power sources. 
26 73 Amateur Radio Today • February 1997 




Photo A. The op-amp voltage multiplier circuit 
used in the Turbo Digi-Sniffer, Point-to-point sol- 
dering using perf board was the selected method 
of construction. Lead length is not critical. 

be accessible from Lhe front of the Turbo 
Digi-Sniffer should be connected to lhe 
junctions at RA, The potentiometer will 
now allow you to change the displayed 
voltage sensitivity. The junction pads at 
RB should remain jumpered together. The 
two PI junctions also need to be jumpered 
together The PI modification sets the 
decimal point on the display as (.000). 

Construction: the rectifier/voltage 
multiplier circuit 

The rectifier/ voltage multiplier circuit 
portion of this project has appeared in 
many electronic "recipe books." Aside 
from containing a passive rectifier 
circuit, it also contains an operational 
amplifier (LM 324) which is employed 



as a voltage multiplier. When coupled 
with a digital voltage display sensitive to 
microvolts, the display will be able to 
essentially detect voltage in the picovolt 
(billionth of a volt) range. This particu- 
lar project will require two 9 volt batter- 
ies. As the op amp section is an active 
circuit design, it will require a 9 volt power 
source. The LCD display will also require 
an additional and separate 9 volt battery. 
Both of these batteries are connected 
through the DPDT switch, The LCD panel 
display pulls less than a mil li amp of cur- 
rent, and because of this low current drain 
on the battery the display battery will last 
a year or more with normal use. 

I elected to mount the rectifier/ voltage 
multiplier circuit on some perfboard and 
point-to-point soldered this circuitry, 
populating the board by surrounding the 
14-pin IC socket with the listed compo- 
nents. The actual circuit layout is noncriti- 
cal, and the mount-and-solder method of 
placing the circuit components on the 
perll^oard does not have to follow any par- 
ticular order as long as it follows the sche- 
matic layout. Since I had a number of 
different types of antennas configured 
with a BNC n I chose to use one of the 
junque box chassis- mount BNC connec- 
tors I had. A UHF-stylc connector or even 
an RCA-style chassis mount connector 
would work fine as a way to connect an 
antenna to the Turbo Oigi-Sniffer* 

Once the rectifier/voltage multiplier 
circuit is complete, connect it to the digi- 
tal display board. As a matter of interest, 
you can keep the cost of the project 
down by using junque box parts. Any 
germanium diodes will work (some may 







Pitoto B. Back of the WD display, showing the silk-screened layout pads for the descried hookup. 



work better than others). The value of 
the RF choke and the capacitor also are 
not critical within the rectifier circuit. 
The aluminum chassis pictured was pur- 
chased at Midwest Surplus for $L95. 
The TXirbo Digi-Sniffer acted a little errati- 
cally when originally built into a plastic 
enclosure, possibly due to capacitive cou- 
pling with lhe hand and the tendency for 
RF to take other paths past the diode and 
choke. An aluminum chassis will rectify 
this situation. The most difficult part of 
this project was ''hogging out" the window 
on the aluminum chassis for the digital dis- 
play. The most time spent, on this project 
was in preparing the chassis, It took less 
than an hour to solder the components 
and leads in place! 

The smoke test 

For initial alignment, the panel meter 
has to be on and you will need access to 
the 10k trimmer and the 10 megohm 
chassis-mounted potentiometer. You 
may need to go back and forth between 
the trimmer pot and the chassis-mounted 
pot to get the initial alignment in the 
ballpark. Try starting with a rubber- 
duck-sized antenna on the Turbo Digi- 
Sniffer and an RF source, such as a signal 
generator. Without a signal generator you 
could use an ofl-hook cordless phone or 
baby monitor. If the field is too strong for 
the counter to resolve or if the gain control 
on pins 8 and 3 of the LM 324 is too high, 
the display wil I go into an over-range con- 
dition, displaying the number 1, with no 
other digits. Tile chassis-mounted 1 me- 
gohm potentiometer controls the sensitiv- 
ity of the LCD display, while the 10k 
trimmer controls the gain level of the volt- 
age multiplier circuit. With the gain all 
the way up on the potentiometer, you 
will see that you will be able to adjust 
the 10k trimmer at the LM 324 to a level 
where there is a zero reading with no an- 
tenna connected to the Turbo Digi- 
Sniffer (with no nearby RF sources), but 
with an antenna connected the display 
will start detecting u far-off * RF sources. 
Be aware that these far-off sources may 
be a local AM or FM radio station, and 
the LM 324 J s gain control can attenuate 
these very weak signals. After proper ad- 
justment, the display should read .000 
with no RF field present. A nearby RF 
field will cause the display to show dig- 
its; the stronger the field, the higher the 
number displayed. 
73 Amateur Radio Today • February 1997 27 



Digital Pcrn# 



I'll 



jpii.'/.l ." '■ 



.a^w^VV. (i ,- 



Pi0^' 



pern©' 




Photo C. Pre-built LCD with analog-w-digirat convener. 



Let's experiment 

I've found thai the Turbo Digi-Sniffer 
is sensitive throughout a wide range of 
frequencies- Also, keep in mind that dif- 
ferent types of antennas on the Turbo 
Digi-Sniffcr wiil also affect sensitivity 
at different frequencies. As this device is 
not calibrated, the emphasis should be 
placed on "relative" (in relative field- 
strength readings). Relative readings are 
extremely useful when checking out an- 
tennas or when out in the field sniffing 
for foxhunt transmitters, Do you want a 
really big scare? Try checking out your 
microwave oven using the Turbo Digi- 
Sniffer. Yes, Virginia, microwave ovens 
do leak! 

When using the Digital FSM to detect 
RF fields, insure lhat the measurements 
are conducted at least two wavelengths 
from the transmitter antenna. Also 



remember to 
keep the Turbo 
Digi-Sniffer's 
antenna at the 
same orienta- 
tion (polariza- 
tion) as the 
transmi tter 
antenna. 
Note that the 
metal chassis 
and the Tlirbo 
Digi-SnilTer an- 
tenna, if brought 
into an optimum 
plane, can be- 
come coupled 
with the trans- 
mitter antenna 
and become a 
part of the radi- 
ating system. 





DIGI-SNIFFER 



Al 












**mmmm 



Photo D> The completed Turbo Digi-Sniffer. 
28 73 Amateur Radio Today 'February 1997 



Talk about some wild field- strength 
readings! 

A perfect club project? 

The cost of all the parts of this project 
can be kept at about $20 with careful 
shopping, and the Turbo Digi-Sniffer de- 
sign is both simple and practical. What's 
stopping you, then, from organizing a club 
project one Saturday morning and putting 
together a barrelful of these useful test 
instruments for all the club members? 



Wanted ! 

Ham related 

cover pictures 

Contact 

Frances 

at 

800-274-7373 



Parts List 


Qty. 


Part# 


Description 


1 


29-01 


LCD panel display 


i 




1 megohm potentiometer 
(chassis-mount) 


1 


4" x 2" x 2-3/4" 


Aluminum chassis 


1 


RF-114 


BNC female chassis mount 


1 


LM-324 


Quad op amp 


1 


1 N4001 


Diode 


2 


1N34A 
(or equiv.) 


Germanium diode 


2 


CD111 


.01 (ljlJF disc cap 






1k ohm 1/4 watt resistor 






10k ohm 1/4 watt resistor 






100k ohm 1/4 watt resistor 


2 




1 megohm 1/4 watt resistor 




VR207 


10k ohm single-turn trimmer pot 




ICS2 


14-pin IC socket 




570-21 


Mini chassis-mount DPDT toggle 
switch* 




JALPC-1 


Pert board (you cut to size) 


2 




9V battery connectors 


Note: All parts can be ordered from Midwest Surplus 
Electronics, P.O. Box 607, 501 W. Main St., Fairborn OH 
45324; (800) 523-3690. 


* DPDT chassis-mounted switches are available at 
Midwest surplus, so they are used here in lieu of the 
DPST (double-pole single-throw) switch used to switch 
on and off the two 9 volt batteries. The double-throw 
portion of this switch is not used for this project. 



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Number 30 on your Feedback card 



Sumas Mountain High 

Building a self-sufficient repeater tower on a British Columbia mountain 



Will lmanseVE7BJD 

211-33370 Nelson Ave. 

Abbotsford BC 

Canada V2S-2L8 



In the center of the 80-mile-long Eraser Val- 
tey in British Columbia, Canada, sits 
3,000-foot-high Sumas Mountain. This 
hill is situated perfectly to give a clear, unob- 
structed view that stretches (from west to east) 
from the east coast of Vancouver Island almost 
all the way to the town of Hope, and south- 
ward into the United States to well past the city 
of Bellingham, Washington. 

Several years ago the hams of Abbotsford 
BC, at the base of the mountain, dreamed of 
putting a repeater on Sumas. Our dream has 
finally become a reality, 

We chose a site on a ridge at 2 J50 feet. The 
Fraser Valley Amateur Radio Emergency Ser- 
vices Society applied for a government lease 
and was approved. Next came the challenge: 
Building and running a repeater site with no 
available power in the foreseeable future and 
very limited vehicle access. 

The designers decided to use solar 
power; later we added wind power The 
British Columbia Telephone Company do- 
nated a 50-foot tower in return for a small 
donation to the Telephone Pioneers of 
America Society, A donation of cinder 
building blocks from the local Blackwood 
Building Supply and Home Hardware store 
helped, too. One of the local hams, an expe- 
rienced bricklayer, was put in charge of 
constructing the building. Another ham 
with cement experience (and a truck for the 
job), took care of the cement work and get- 
ting the materials to the site. The tower 
work was done by a ham who worked in 
the Lower construction field. Teamwork and 




Photo A. Storms are common up here, so the 
guys are heavy-duty, 

30 73 Amateur Radio Today * February 1997 



cooperation from a number of other hams 
helped create a professional-looking site. A 
small solar-powered commercial site not too 
far irorn ours looked amateur by comparison! 

We erected the 50-foot tower next. We 
drilled down into the stony mountainside 
three feet in four places for the base and ep- 
oxied threaded steel rods into the rock. The 
tower was then put into position, with a 20- 
foot-diameter H fixture installed at the top 
for the antennas. The vertical pipes at the 
end of the H fixture were extended above 
and below for both upper antenna and 
lower inverted antenna mounting. This al- 
lowed for eight antennas to be mounted on 
the tower without having to mount them on 
the face of the tower itself. We also added 
an anti-climb shield and gate to keep 
unauthorized visitors off the tower. 

The tower was supposed to be sclt-sup- 
porting, but with the amount of weight at 
the top we decided to add guys. As you can 
surmise from Photo A, the mountaintop 
winds can be fierce. 

Next, we added a donated chain link 
fence, then a second tower — an 80-foot 
guyed tower, donated by the local Rogers 
Cablevision outlet, It was also installed 
with two H fixtures, providing room for six 
more antennas. With some more small do- 
nations to the Telephone Pioneers, we ob- 
tained some antennas and heliax 
waveguide. 

The main VHP repeater is on J 46.60 
MHz and the UHF repeater is on 442.025 
MHz. We also have a packet repeater, a full 
duplex UHF link for phone patches to 
Abbotsford, and a 1 .2 GHz FM amateur 
television repeater with two remotely-con- 
trolled cameras, mounted on the two tow- 
ers. These cameras can be tilted and panned 
by tone control. They allow us to check con- 
ditions and monitor any intrusions at the site. 
They also allow fantastic views up and down 
the valley. An outside speaker and microphone 
can be activated remotely to communicate 
with people at the site. A planned motion de- 
tector with announcement on the VHF 



repeater will also alert us to any intruders. 

All the equipment runs from 1 6 solar panels 
at the site. Eight are located on the roof of the 
building; the other eight are on one tower. The 
panels on the tower can be for winter and 
summer sun angles. 

We've tried a number of windmills, but so 
far four of lliem have self-destructed. The first, 
a 75 watt model, lasted a few months. The 
next three were 300 watt models. One lasted 
less than a day, and another less than a week — 
and that after the manufacturer assured us that 
they were almost indestructible. The current 
300 watt model is still running — we're 
keeping our fingers crossed. 

At the same time, we ako put up a 55-fool 
self-supporting tower in the town of Hope, 50 
miles to the east. A VHF repeater at 147.08 
MHz was installed in a cabinet on the side of 
the tower Now we're working to link the 
Abbotsford and Hope repeaters, and then ex- 
pand farther east via links into British 
Columbia's interior. 

We're proud to have built such an im- 
pressive repeater site. Our group has solic- 
ited all the donations to the cause, and in 
some cases donated our own equipment 
and funds. The cooperation among the 
group of amateurs that took on this project 
was first rate. There was seldom a problem 
securing volunteers for a work project. This 
is what amateur radio is all about. ES 




Photo B* Keeping some spare cables ami other 
items on hand helps. The main and secondary 
2m repeaters are visible on the left. 



Never shy die 

Continued from page 4 

ihird the cost. With the number of govern- 
ment employees now outnumbering our 
manufacturing force, it does tend to make 
everything we let the government buy for us 
cost at least three times normal, And that's 
on a good day. 

If Congress would allow competition, 
we'd have private mail services providing 
two deliveries a day, with first class mail for 
100, according to expert estimates. If you'd 
like 10 get really upset over our mail service, 
read Monopoly Mail by Douglas Adic, 
Transaction Publishers, Rutgers University, 
New Brunswick NJ 08903, ISBN 0-88738- 
747-0, 197p. 

As long as you're content to work the first 
four hours of every day for the government 
and the rest of the day for yourself, the situa- 
tion is just going to get worse. Yes, the gov- 
ernment comes first. They get your money 
without your ever even seeing it. 

What can you do about the mess? Well, 
I've already explained that. Let me boil ii 
down for you, L Never re-elect anyone. 
Keep flushing the political toilet. And don't 
re-elect anyone ever again in the future. We 
don't need to worry about term limits if 
you'll flush the toilet every two years. 2. 
LetVs get some hams into our state 
legislatures. 

Justice 

A letter from a reader mentioned that the 
medical industry scams are at least matched 
by our criminal justice system. 1 love the eu- 
phemism. Justice system, indeed. And how 
about our "correctional facilities"? That's 
about the last thing they do* Anyway, Leigh 
writes, "They don't care who's guilty, they 
just need convictions, and they need to keep 
the minorities stirred up just tor job security. 
They will gladly send an innocent person to 
prison to further their careers. I'm told that 
Sandra Day O'Connor made it to the Su- 
preme Court on cases where the evidence 
was manufactured by a crooked lab that used 
to operate in Phoenix. After their methods 
were discovered they closed shop and moved 
their business to Texas, but very few cases 
were retried as a result." 

Surely Leigh must be exaggerating. No 
American would ever do anything like that, 
would they? For some reason that reminds 
me of when I was a TV producer-director 
and I got to know a New York City police de- 
tective who wanted to blow the whistle on 
what was going on. For instance, he told me 
about a cooperative dentist just down the 
street from the station house where they'd 
take prisoners. The dentist would drill the 
guy's teeth with no pain killer, right down 
into the nerve, one after the other, until he 
signed a confession, The dentist would then 
fill the teeth and nobody could prove any- 
thing. He said they always got confessions. 
The expos£ program we were planning fell 
apart when my friend suddenly disappeared. 
He's never been heard of again. 



I also remember my first court case in 
New York, i had a simple open and shut 
case, but my lawyer said 1 would have to 
give the judge $5,000 if I wanted to win. I 
didn't see how there was any way to lose so 1 
didn't pay. I lost, 

Then there was the time 1 was a witness in 
a murder case where I had critically impor- 
tant testimony to give and was not allowed to 
give it. The murderer got off with a slap on 
the wrist. So much for swearing to tell the 
truth, the whole truth, and nothing but the 
truth. Not in our courts. 

There sure are a lot of things we need to 
fix to make this the country it could and 
should be. 

Though Tve had millions stolen from me, 
with no punishment for the thieves, Fm still 
optimistic. Heck, I can always make more. 

Have you had any interesting experiences 
with our "justice" system? 

AIDS, HIV, and Other Baloney 

Yes, Fve been reading again, and it wasn't 
the new ARRL Handbook either. Unless you 
know someone with HIV or AIDS (or both), 
or are curious about all the fuss, you may not 
be interested enough to go out and buy the 
new Peter Duesberg book, Inventing the 
AIDS Virus. It's a $30 722-pager and it nails 
the medical establishment to the wall for the 
mess it's made of this whole business. 

Since Fve read in several places that there 
are thousands of AIDS patients who are HIV 
negative, and millions of HIV positive 
people with no sign of AIDS, Duesberg's 
claim that AIDS is a lifestyle disease, par- 
ticularly involving the use of recreational 
drugs, makes sense. He further provides ex- 
haustive proof that AZT, which is a chemo- 
therapy used to treat AIDS, actually is re- 
sponsible for causing AIDS. He also pro- 
vides proof that AIDS is not in the slightest 
infectious. 

AIDS is actually the result of a toxic 
buildup from drug use. Remember the drug 
culture of the '60s? Well, is it really all that 
surprising that people's bodies eventually re- 
acted a few years later? And since drug use is 
particularly rampant in the homosexual cul- 
ture, this explains why the syndrome hit this 
group so strongly. It's similar to cigarettes, 
where it takes a few years of poisoning one's 
body with nicotine and tars before emphy- 
sema, heart trouble, lung cancer, and other 
illnesses caused by defeating the body's im- 
mune system inevitably appear. These drugs 
lower the effectiveness of the immune sys- 
tem, allowing any opportunistic disease to 
win out. 

Our bodies harbor billions of microbes. In- 
deed there are more microbes than cells in our 
bodies, so our Immune system is in a constant 
war with invaders. Anything that tends to lower 
the immune system can allow the bad guys to 
win. Our immune system suffers when we are 
stressed, when our bodies don't get the re- 
quired nutrients, if we shortchange it on water 
or oxygen, or load in toxins. 

Continued on page 40 




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73 Amateur Radio Today • February 1997 31 



Number 32 on your Feedback card 



Add a Microphone Preamplifier to 

Your 10 Meter Rig 

Low-cost speech processing can increase your power. 



Phil SalasADBX 
1517 Creekside Drive 
Richardson TX 75081 



Over the past few months I've 
been playing around on 10 
meters. Ten meters does open up 
even in these days of low sunspot activ- 
ity, and due to the large number of 
Novice and Tech-Plus hams, there is 
enough activity on 10 meters that it's 
pretty easy to know when band open- 
ings do occur. Also, there are some tre- 
mendous bargains available in 10 
meter rigs. The Uniden, Ranger, Lin- 
coln, Emperor, and Radio Shack 10 
meter rigs are showing up at very good 
prices (I guess the folks who bought 
them during the sunspot maximum are 
dumping them because they think 10 
meters is dead most of the time). 



I currently own both a Uniden HR- 
2600 and a Radio Shack HTX-100. (I 
know, I know — why do I need both a 
Uniden 2600 and a Radio Shack HTX- 
100? Well, we have two cars! See how 
easy it is to justify multiple rigs?) 
Anyway, when running some tests on 
these radios, I saw a very distinct aver- 
age output power variation between 
these rigs. On my analog power meter 
(Diamond SX-1000), average talking 
power is around 5-6 watts on the Ra- 
dio Shack HTX-100 and only about 1- 
2 watts on the Uniden HR-2600, 
Looking at the S- meter on my test re- 
ceiver (my Icorn IC-706), I saw a 2(!) 
S-unit peak difference in favor of the 



+8 VDC 



0.1 jiF 



4.7 \xF 



From Mike 0J uF 




To Radio 



Fig. |* Dynamic microphone preamp. 

32 73 Amateur Radio Today • February 1997 



Radio Shack radio. With both the Ra- 
dio Shack and Uniden radios, I could 
whistle-up the power to the advertised 
25 watts output; however, the Radio 
Shack rig did a much better job of 
keeping the "talking power" up. 
HmmiTL So what could I do to my 
Uniden to make it better? 



u 



Up" your talk power 



After examining the Uniden 2600 
schematic (with a magnifying glass — 
it is small!), I determined that there is 
no obvious microphone gain adjust- 
ment in the radio, so I decided to build 
in a microphone preamp that would 
give me equivalent "talk power" to the 
Radio Shack rig. My final circuit is 
shown in Fig. 1. 

I selected the RC values to give 
around a 300 Hz high pass, and a 3,000 
Hz low-pass cutoff, I traced the 
Uniden microphone connections to the 
main board (red and black wires), cut 
the red (hot) wire and inserted the cir- 
cuit shown. For powering, 1 probed 
around on the PC board until I found a 
source of 8 VDC (regulated) and 
ground and tapped into these points, 

Then } while talking into the micro- 
phone, I adjusted the potentiometer 
for the same 5-6 watts average 
power as seen on the Radio Shack 
rig. I also listened to my voice on 
my IO706 and verified that there 
was no distortion. My final tests oc- 
curred on the air. Comments from 
stations I worked included ''excel- 
lent audio" and "good crisp modula- 
tion." I highly recommend the 
addition of this preamplifier circuit 
to your Uniden radio. 



+8VDC 




+ 4.7 uF 



Electret Mike 
Element 




4.7 jiF 



To Radio 



Fjrg. 2. Electret mike element powering . 



Change the mike element 

A friend of mine, Bob N5UPF, 
owns a Uniden 2510. This radio had 
a dead microphone. Since the 
Uniden 2510 and 2600 share the 
same microphone, I borrowed Bob's 
radio to check the "average*' power 
and found it to be similar to that of 
my unmodified HR-2600. I also 
verified that Bob's microphone ele- 
ment was dead. Finding a replace- 
ment dynamic microphone element 
for this microphone is difficult, and 
dynamic elements are relatively ex* 
pensive. Since Bob's 2510 could 
benefit from increased microphone 
gain, I decided to substitute a Radio 
Shack electret microphone element 
for the dynamic clement. These clcc- 
iret elements are very small, inex- 
pensive, easily obtainable, and they 
have gain. 

Unfortunately, these mike ele- 
ments also require powering — but 
this turned out to be a pretty easy 
fix. First, I stuffed the new tiny elec- 
tret element into Bob's microphone 
case, added a drop of epoxy to hold 
it in place, and then packed a piece 
of foam rubber behind it to fill the 
large cavity left by the dynamic ele- 
ment. Next, I traced the microphone 
wires into the radio. The hot wire 
turned out to be a yellow wire in a 
large, connectorized bundle of 
wires. I cut this yellow wire and in- 
serted the circuit shown in Fig- 2. 
Again, I probed around on the PC 
board to find a source of regulated 8 



VDC and ground. Anyway, when ev- 
erything was finished, I ran my "av- 
erage" power tests while adjusting 
the potentiometer so that Bob's 2510 
put out the 5-6 watts of the HTX 100 
and my preamplified HR-2600. 

Since I completed the above 
projects, my HTX-100 microphone 
failed. What is it about these dy- 
namic elements? Anyway, I built the 
same electret element and powering 
circuit as shown in Fig. 2 into my 
HTX-100. In the HTX-100, the front 
panel circuit board uses solder 
bridges to attach to the main circuit 
board, I probed around on the solder 
bridges until I identified the micro- 
phone "hot" wire, removed the sol- 
der bridge, and substituted the Fig* 2 
circuit across the gap. An adjacent 
solder trace had the 8 VDC I needed 
for powering the mike element. 
Again, I adjusted the potentiometer 
for the 5-6 watts average power 
output on my analog power meter. 

Some radios can probably benefit 
from increased mike gain — I know the 
Uniden radios do. It is pretty easy to 
build a microphone preamp or replace 
a dynamic mike element with an elec- 
tret mike element. Since the Uniden 
radios use ALC to limit the maximum 
transmit power, we are effectively get- 
ting some audio speech processing due 
to the combination of additional mi- 
crophone gain and ALC limiting. Fi- 
nally, both of these circuits are 
physically small and easily fit inside 
most any radio. Now if 10 meters would 
just open up a little more often! 



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73 Amateur Radio Today » February 1 997 33 



73 Review 



Number 34 on your Feedback card 



Hamtronics RWX Storm Watch 
Weather Broadcast Receiver 

Hams need to know about storm emergencies. 



Dean Lewis WA3WGV 
1193 Azalea Lane 

Palatine IL 60074 



The NOAA Weaiher Radio (NWR) 
broadcast system transmits on 
seven discrete 25 kH/.-spaccd fre- 
quencies between 162.400 and 162.550 
MHz from over 425 stations covering all 
50 stales, adjacent coastal waters. Puerto 
Rico, the US. Virgin Islands, and LLS. 
Pacific Territories, The system currently 
covers 70 to 80 percent of the U.S. popu- 
lation; the current expansion program 
will increase coverage lo 95 percent. 
NWR has been designated as the sole 
government-operated radio system to 
provide direct warnings for both natural 
disasters and nuclear attack, with plans 
to include warnings for alt hazardous 
conditions thai pose a threat to life and 
safety, both at a local and national level. 

The Hamtronics model RWX is a 
highly sensitive and selective, profes- 
sional quality seven-channel crystal-con- 
trolled double-conversion FM superhet 
receiver for the 24- hour NWR broadcasts 
from the National Weather Service 
(NWS). You can listen lo the current 
weather report and forecast at any lime: 
or, when set to "Stoma Watch."' the re- 
ceiver will remain silent until it receives 
an alert tone from the transmitting sta- 
tion, opening the squelch so the user can 
hear the emergency information that fol- 
lows. Crystals for all seven NWR 
channels are supplied 

The receiver provides room-filling 
volume at less than a quarter turn of the 
front-panel control, \u there's plenty of 
reserve for noisy locations, mobile use. 
or to hear alarm-activated announce- 
ments in another room. Circuit board 
terminals are provided for an external 
34 73 Amateur Radio Today * February 1997 



speaker. Sensitivity and selectivity are 
excellent. For all the audio volume and 
features, the assembled unit is a conve- 
nient size. The alarm output can be used. 
through a relay, to drive secondary 
alarms for those with special needs: a 
loud bell, flashing light, bed-shaker, etc. 
In its full kit or assembled form, the re- 
ceiver comes with a high quality plug- 
in-the-wall power supply. For temporary 
portable use it can be powered by any 
source from a car cigarette lighter to 12 
vol is worth of A A cells, or a 9 volt 
battery. Watch battery polarity carefully. 



"The Hamtronics model RWX 
is a 'must have 9 for hams or 
for anyone else involved in or 
affected by emergency opera- 
tions due to weather" 



The RWX is available in kit form, 
with or without the cabinet/speaker/ AC 
power supply, or fully assembled, tested, 
and installed in the enclosure. Appropri- 
ate assembly and7or operations manuals 
are supplied with the radio in cither case. 

Circuit description and assembly 

RF input at 162 MHz is amplified by a 
low -noise dual -gate FET. Double- tuned 
circuits provide rejection of images and 
out-of-band signals. The first mixer con- 
verts the 162 MH/ input to the first IF 
frequency. 10.7 MH?, which goes 
through a ceramic filter on its way to an 
integrated circuit IF amplifier. The injec- 
tion signal for the first mixer comes 
from a 16 MHz oscillator controlled by 




the seven switched frequency systoles. 
The signal is tripled twice, with 
double-tuned circuits in each tripler. 

The IF amplifier chip contains a crys- 
tal-controlled 10.245 MHz oscillator, the 
second mixer with an output at the sec- 
ond IF frequency (455 kHz), a 
narrowband ceramic filter, and a quadra* 
lure detector. The 1C audio output is ap- 
plied through the volume control lo an 
IC audio amplifier chip, which supplies 
both the i meruit] and external speaker 
terminals on the circuit board. 

The IF amplifier chip also provides 
the tone alert squelch function, respond- 
ing to the 1050 Hz NWS-transmitted 
alerting tone. 

Like their RWWV receiver (sec re- 
view in 73, December 1995) , the circuit 
board is FR^l, double-sided, with a con- 
tinuous ground plane on the top surface: 
all holes are drilled and plated-through. 

Follow the detailed assembly instruc- 
tions carefully; the suggestions and 
clues are invaluable for getting good re- 
sults. As in any VHF circuit, short leads 
are important. This is a quality circuit 
board; the parts all fit well, holes are 
properly positioned, and components 
solder in easily. 

Following the assembly; an RF sicnal 
generator and a sensitive DC voltmeter 
are needed for alignment; full step-by- 
step instructions are included. Tables of 
(eM voltages are provided: if you can 
build and align the receiver, you can 
troubleshoot it if necessary. In case you 



move or take the receiver to other loca- 
tions, make a copy of the "Switch Posi- 
tion vs. Channel Frequency" list from 
the instruction manual and tape it inside 
the receiver. 

Performance 

A seven-position DIP (dual inline 
package) switch, or rather, set of 
switches, selects the crystal-con- 
trolled frequency, The switches are 
mounted on the circuit board, and 
are easy to operate with a small 
straight-blade screwdriver With 
the frequency selected and the re- 
ceiver closed up, only the necessary 
controls are available on the front 
and rear panels: volume control, Re- 
set/Auto/Listen switch, a Storm 
Watch LED, and the BNC antenna 
connector. 

Operation is straightforward. To 
listen to the current broadcast, set 
the front panel switch to "Listen." 
Pushing the switch all the way to the 
left and releasing it puts the receiver 
in "Auto" mode and turns on the 
Storm Watch LED, The radio will re- 
main silent until it receives an 
NWS-broadcast alert tone. The tone 
opens the squelch and activates the 
audio at your pre-set volume. 

The quality 12 VDC plug-in power 
"brick" supplied with the receiver 
provides hum-free reception. 

The BNC antenna fitting is 
mounted on the rear panel; get a 
right-angle adapter for mounting an 
antenna right on the radio. From my 
location northwest of Chicago, a 
quarter-wave whip on the back of 
the receiver provides loud/clear re- 
ception of the NWR signal off the 
Sears Tower, 28 miles away (but 
then, so does a 3-inch length of 
wire!). The whole idea, of course, is 
reliable reception of your local NWR 
station, but I couldn't resist trying a 
little DXing, On a warm afternoon, 
with tropospheric propagation helping 
out, the following came in clear and 
strong with a 2 meter AEA "Hot Rod" 
antenna (telescoping end-fed half- 
wave), indoors: Rockford, IL (54 mi.); 
Milwaukee, WI (65 mi.); Grand Rap- 
ids, Michigan (140 mi.); Adams, Wis- 
consin (160 mi.). (Consider the 
additional value of the NWR stations 
as 2 meter propagation beacons!) 



If you're located anywhere near an 
NWR transmitter, you should have 
no problem with a small indoor an- 
tenna. In more rural areas, try an 
outdoor ground plane, or even a ver- 
tical yagL RadioShack™ carries a 
line of "scanner" antennas that 
should work well; amateur 2 meter 
antennas should work just fine. 

I've owned weather receivers be- 
fore. Some have been good for little 
more than modification to monitor 
local 2 meter repeaters, some have 
had serious intermod problems, and 
most have lacked sensitivity. This is 
my first that could be called a seri- 
ous, professional-grade receiver, in- 
cluding the tone alert function; it 
provides a real measure of confi- 
dence that important emergency 
information will not be missed* 

Call your local office of the Na- 
tional Weather Service for the local 
frequency (or just switch through 
the seven frequencies until you find 
it), and the day and time of their 
tone-alert test. Most seem to be on 
Wednesdays at noon (ours happens 
to be Tuesdays at 11:00 a.m.). While 
you're at it, ask for the current loca- 
tion/frequency list bulletin and other 
information on NOAA Weather Ra- 
dio they have available. It's a good 
idea to monitor the tone alert test oc- 
casionally, to ensure proper activation 
of the Storm Watch function. 

Conclusion 

The Hamtronics model RWX is a 
"must have" for hams, CAP, Coast 
Guard Auxiliary, Police and Fire De- 
partments, schools, hospitals, truck 
and taxi dispatchers, Scouts, out- 
doors enthusiasts, or anyone else in- 
volved in or affected by emergency 
operations due to weather. It's easy 
to use, well-built, sensitive, and 
dependable. 

The RWX is available as a board- 
level kit for $79; board, cabinet, 
speaker, and power supply in kit 
form for $99; or fully assembled and 
tested with the cabinet, speaker, and 
power supply for $139. 

For further information, a catalog, or 
to order the RWX, write to Hamtronics, 
Inc., 65 Moul Road, Hilton NY 14468- 
9535, or call them at 716/392-9430; FAX 
716/392-9420. 



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73 Amateur Radio Today ■ February 1 997 35 



*« 



Number 36 on your Feedback card 



The Telegraph 

A little device that changed the world. 



L VanProoyen K8KWD 

8330 Myers Lake NE 

Rockford Ml 49341 



As we approach the millennium 
in this "information age/* we 
have access to a variety of com- 
munication technologies. This is the 
story of how the forerunner of them all. 
the electric telegraph, came to be. 

The Morse code 

Di-di-dah-dah-di-dit — dots and dashes. 
When you hear the sound, you most 
likely ihink of Morse code— right? Bui 
did you know that Samuel Finley Breese 
Morse's original telegraph system was 
not based on sound at all? 

Dating back to the mid 1 830s, Morse's 
original "receiver" was a lot tike a chart 
recorder. It marked patterns of the mak- 
ing and breaking o\ an electrical circuit 
at the sending station onto paper tape. 
The sending station "keyed" the circuit 
according to an early code devised by 
Morse, a forerunner of the familiar dot- 
and-dash code still in use today — and 
the traditional telegraph key (Photo A) 
hadn't been "invented** yel either. 

Only much later using a modified re- 
ceiver, clever "operators" learned to rec- 
ognize rhythm patterns in the receiver's 







Photo A. The telegraph key. 

36 73 Amateur Radio Today * February 1997 



"click-click" sound, and found that they 
could translate directly from sound to 
text This receiver was subsequently re- 
Fined into the familiar "sounder^ similar 
to that shown in Photo R, 

Morse is perhaps best known for the 
code that tears his name, but his ap- 
proach to developing an electric tele- 
graph, pioneering the simplex circuit 
(one wire pair) and using a quasi-digital 
signaling code, was unique. It made 
building a telegraph system possible and 
led to the communications systems we 
use today. 

Following early trials. Morse's tele- 
graph rapidly spread throughout 
America in the 1850s. Morse code, as il 
evolved, went on to become a world 
standard that has lasted over 175 years. 
As wireless and radio came of age, the 
merchant marine also adopted the code 
as its international standard, pretty 
much assuring the US a position of 
technological leadership in the field of 
telecommunication. 

"Now closing down continuous watch. 
Fair winds and following seas with 73s 
from all of us." With this transmission at 
8 PM (0000 Hour* GMT). July 31, 1993, 
the U. S. Coast Guard ended nearly 50 
years of continuous watch on 500 kHz, 
the international maritime distress fre- 
quency. On March 31, 1995, the Coast 
Guard discontinued all other regularly 
scheduled use of Morse code. Today, 
there is virtually no formal use of the 
Morse code bv the US Coast Guard or 
military. Newer technology — satellite 
communication, ship-io-shore teleprinters. 



and the like — is said to have made Morse 
code obsolete. 

Technology changes but the need to 
communicate continues. Today, there are 
many technological choices, and high 
speed data systems have great impact on 
almost everyone's life. Computers, 
linked by digital data systems, virtually 
run the world. 

Information is readily available. The 
data highway, Internet, packet webs, cellu- 
lar phones, and cable are examples. Get- 
ting the message is not the problem il was 
in the '40s (1840s, or for that matter, 
1940s). Perhaps knowing what to do with 
all the available information, differentiat- 
ing quality from junk, is today's problem. 

Standing on giants" shoulders 

As with virtually all inventors, Morse 
didn't start in a vacuum! In the 1830s, 
many dreamed of building a telegraph, and 
some already had telegraph schemes on 
paper. By the time Morse started develop- 
ing his ideas, a few others were well un- 
derua\ in [lerfeeting theirs. Chief among 
these were Charles Wheatstone and Ed- 
ward Daw. both from England, and both 
received British "lelegraph" patents by 
1837. 

Wheatstone, now known largely for the 
Wheatstone Bridge, was an electrical ex- 
perimenter in the 1830s. He gained early 
notoriety designing a method which rather 
accurately measured electrical propagation 
speed through wire in 1 834. The system used 
a rotating mirror scheme similar to the classic 
Michelson velodty-of-light experiment. 



Wheatstone went on to develop his 
telegraph over the following years. It 
initially used five circuits, each termi- 
nated with a galvanometer-like device 
(Photo C). Each such device had a 
pointer that could assume any of six po- 
sitions according to the current level in 
its circuit, and with five circuits, Wheat- 
stone could communicate 30 charac- 
ters — albeit very slowly. Because of the 
five-line requirement and message cod- 
ing/decoding difficulty, it was doomed 
to failure as a practical telegraph system. 
However, Wheatstone's galvanometer 
detector would later be modified to use a 
mirror as the indicator and find applica- 
tion in the first Atlantic telegraph, but 
that's another story* 

Later, working together with William 
R Cooke, another telegraph inventor of 
the time, Wheatstone refined the design 
to require only three circuits and indica- 
tors. This basic system would find early 
use in England and parts of Europe. 

Edward Davy also received a British 
telegraph system patent in 1837 because 
of a couple unique features his system 
had. It was a multi-wire device like 
Wheatstone's and Cooke's, but Davy de- 
signed a repeater circuit which in itself 
would find later use by others in 
relaying signals over long distances. 

In Germany, experimenters made an 
early discovery that would also be of use 
to later telegraph builders. They discov- 
ered that a single wire could be used in a 
(telegraph) circuit if the earth were used 
to complete the circuit pair (one leg 
grounded at each end of the link). This 
discovery was not generally known until 
after 1 837, so Morse did not make use of 
it initially. Also, Morse's first major test 
link was begun using an underground 
line which would have been difficult to 
insulate, given the state of wire 
insulation quality at the time. 

There was another development, in 
electrical technology which would prove 
beneficial to telegraph builders — the 
battery. Until its emergence, most elec- 
trical experimenters were limited to us- 
ing a galvanic cell which produced 
about 1 volt, John William Daniel 1, an 
Englishman, discovered that cells could 
be connected in series to form a battery. 
The increased voltage available from 
such a battery would solve many prob- 
lems caused by wire resistance and other 
circuit losses in telegraph lines. Keep in 
mind that while Georg Ohm had already 



formulated his "Ohm's Law/' these prin- 
ciples were still a mystery to most 
electrical experimenters of the time. 

America's Joseph Henry was another 
contributor to the telegraph's develop- 
ment by providing advice and theory on 
electromagnetics. Since most of the con- 
tending electric telegraph systems em- 
ployed some sort of electromagnetic 
receiving device, the emergence of sen- 
sitive and efficient electromagnets 
solved a major problem impeding the 
development of long lines. 

There were many more contributors 
whose ideas were "borrowed*' and used 
in the development of the electrical 
telegraph. 

Putting all the pieces together 

Exactly how Morse acquired the vari- 
ous pieces of technology needed to pro- 
duce a functional cross-country electric 




Photo B> The sounder as shown was used in 
telegraph offices beginning in the second 
half of the nineteenth century, and many 
were still in use through the 1930s. 

telegraph has long been debated. His 
early notes, for example, indicate he had 
a basic knowledge of electromagnetic 
devices. How he acquired this knowl- 
edge was the basis of a lawsuit brought 



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73 Amateur Radio Today * February 1 997 37 




Photo C% A modern version of the galvanom- 
eter. Used today as a laboratory instrument, 
its development was one of the earliest ex- 
amples of converting an electrical current 
into mechanical motion. 

by one Dr. Jackson, a fellow passenger 
on a ship carrying Morse across the At- 
lantic in 1832, Morse had.. been traveling 
in Europe, purportedly trying to further 
his career as an artist. It is generally 
thought that until his trip back to the 
United States, Morse didn't know what a 
telegraph was — but by the time the ship 
docked, Morse had compiled fairly com- 
plete design notes which he subse- 
quently used in building his first 
telegraph. Jackson, a chemistry profes- 
sor and amateur electrical experimenter, 
would later claim the telegraph idea was 
his. One of the many mysteries of tech- 
nology. I suppose there are other ex- 
amples, but in researching the history 
of electrical communications, I was 
surprised by the number and the feroc- 
ity of the legal battles associated with 
it! 

Morse, though well educated, always 
had a lough time earning a living, com- 
pounded by the burden of raising his 
children alone, his wife having died 
quite young. This, coupled with living 
an artist's life, made him quite familiar 
with tough times. Had he not known 
trouble, though, he might not have had 
the personal fortitude necessary to get 
through the many ordeals he would face 
during his telegraph system's initial 
development. 

Things weren't going too well... 

In 1835, Morse got a teaching post at 
the newly organized New York City 
University as a literature professor. This 
was fortunate because it allowed him ac- 
cess to some of the university's facili- 
ties, and he needed lots of space to set up 
his equipment and carry on experiments 
38 73 Amateur Radio Today * February 1 997 



between classes. He also found access to 
resources and other help unique to a 
university's environment. 

One such resource turned out to be Dr. 
Leonard Gale, a chemistry professor 
also at the university, and knowledge- 
able in electricity. Gale was familiar 
with the Daniell battery and convinced 
Morse to try using it. They were to form 
a lifelong friendship. 

Gale also spotted deficiencies in 
Morse's electromagnet designs and pro- 
vided him with information about Jo- 
seph Henry's earlier work. This lead to 
Morse's producing electromagnets with 
many more turns of wire than he had 
ever before used, resulting in much 
superior performance. 

By 1837, Morse had several hundred 
feet of wire strung around the univer- 
sity halls enabling him to stage 
demonstrations and test various im- 
provements. Also in 1837, news of 
Wheatstone's British telegraph patent 
was getting around, which prompted 
Morse to register his work with the US 
Patent Office. 

Actually Morse had received a copy 
of a letter circulated a year or so earlier 
by the US Treasury seeking ideas for es- 
tablishing a government telegraph sys- 
tem, and he replied with a description of 
his system, as it stood, in 1836. Re- 
sponding as he did, at the time he did, 
was fortunate for Morse, as this letter 
would later be his strongest claim to 
patent rights for his system. 

During Morse's tenure at the univer- 
sity, he staged several demonstrations of 
his system as new developments were 
added, During one such showing in 
1837, a young man named Alfred Vail 
turned up. He was so impressed by the 
telegraph that he recruited the interest of 
his lather, George Vail, owner of the 
Speedwell Iron Works in Morristown, 
New Jersey, a successful manufacturing 
business of the time, 

Morse's partners 

As a single parent on a meager uni- 
versity salary, Morse hadn't been able 
to invest much money or time in his 
telegraph. The Vails, on the other 
hand, had money — at least Alfred's fa- 
ther did, and they were willing to in- 
vest some in Morse's telegraph. Alfred 
also wasn't terribly busy at the time 
and had time to spend on it. 



Besides money, Alfred Vail brought a 
good mechanical aptitude to the tele- 
graph project, having acquired it hang- 
ing around his father's iron works. 
Morse's strengths lay more in the ab- 
stract: ideas, research, etc., and thus his 
equipment lacked both electrical and 
mechanical sophistication prior to 
Alfred's showing up. 

With Alfred on the job, things began 
taking on a new look. By early 1838, the 
two men had perfected the system to the 
point where it was ready to come out of 
the laboratory. 

They made good partners. One of the 
first innovations to come out of the 
Morse- Vail partnership was redesign of 
the receiver. They changed it such that 
the paper tape marker now moved verti- 
cally, up and down, thereby marking the 
paper with dots and dashes instead of the 
previous zigzag pattern. At this point, 
copying was still done by translating the 
marks from the tape after the entire mes- 
sage was received. This new receiver did 
make a click-click sound as it marked 
the paper tape, though. 

Another significant improvement 
made during this time was replacement 
of Morse's old cam strip sending system 
with a "key/* Morse's cam strip was akin 
to a teletype machine's punched paper 
tape and required that the message be 
composed prior to sending. The addition 
of a key allowed direct sending in real 
time. 

From 1838 on, the Morse and Vail 
Partnership would endure. During this 
time, Morse also acknowledged his old 
university colleague, Dr. Leonard Gale, 
as partner because of Gale's earlier elec- 
trical contributions to the system. Morse 
also recognized Vail's father, George, as 
a partner, largely because of the money 
George spent on the project. Later, 
Morse would find other "partners" he 
didn't know he had! 

A government partnership 

While the Vails had deep pockets, esti- 
mated costs for building a test line, even 
over the relatively short distance of 50 to 
100 miles, was more than they were 
willing to spend at the time. 

Morse himself didn't have the money, 
and other investors were reluctant to in- 
vest because as yet, no one could see the 
telegraph as being economically viable. 
A telegraph, though now possible, was 



largely regarded as somewhat of a nov- 
elty, Faced with this, Morse decided to 
turn to the government, and began trying 
to sell the Congress on funding the first 
line. 

In February, 1838, having seen an 
impressive laboratory demonstration, 
a Congressional Committee recom- 
mended an appropriation bill to build an 
experimental line, but the bill failed to 
pass. For the next two years, the Morse 
system sat idle while Morse tried to raise 
money for the project. 

During these two years, Morse trav- 
eled to Europe seeking foreign support. 
While there, he approached the English, 
French, Germans, and Russians in a fu- 
tile attempt to obtain backing. As one ac- 
count goes, he was rather badly received 
in England where Wheatstone was busy 
promoting his system, and as another 
story goes, he managed to alienate the 
Czar of Russia so completely that any 
mention of the Morse telegraph was 
banned in Russia. Morse fared no better 
anywhere else either — -foreign diplo- 
macy was not his calling. He didn't raise 
a dime! 

Tail dragging, Morse returned to a 
rather interesting homecoming. Upon ar- 
rival in New York, he found he'd been 
sacked by the university, which was be- 
set with hard times of its own. Professor 
Gale, his old friend and partner, was also 
affected and forced to find a new job out 
of town. Morse then learned he was be- 
ing sued by good old Dr. Jackson over 
whose idea the telegraph really was. Fi- 
nally, to completely round things out, 
Morse learned the Patent Office had is- 
sued Wheatstone the first US telegraph 
patent ahead of his own pending 
application. 

Although things looked grim, Morse 
continued to lobby Congress to fund the 
project over the following three years. 
During this time, he was reduced to ab- 
ject poverty, relying on tutoring art stu- 
dents to make ends meet. Finally, by 
March 3, 1843, the appropriation bill 
passed the legislature and was signed by 
President Tyler Persistence had paid off 
at last! 

"What hath God wrought?" 

Morse had already given up hope for 
1843, believing this legislative year 
had come and gone like those previ- 
ous. Ann Ellsworth, young daughter of 



a Washington official, delivered the 
news of the appropriation bilFs pas- 
sage to Morse a day later. In gratitude, 
Morse promised her she could name 
the first message to be sent over the 
completed line* 

The experimental line was to link 
Washington with Baltimore. Origi- 
nally, Morse and company planned to 
bury the line underground due to fears 
over possible damage by the elements. 
Unfortunately, that failed after almost 
nine months of construction, when it 
was discovered the wire insulation 
used was inadequate. Switching gears, 
they started stringing wire on poles 
overland. On May 24, 1844, with 
Alfred Vail in Baltimore monitoring, 
Ann Ellsworth handed Morse her mes- 
sage* It was from the Book of Num- 
bers, "What hath God wrought?" 
Morse personally tapped it out from 
Washington, Within minutes, Vail sig- 
naled back that he had the message 
and repeated it back over the line as 
proof the system worked. 

The inauguration of the first opera- 
tional link initially received a lot of at- 
tention in 1844, but there wasn't exactly 
a stampede of people wishing to send 
telegrams from Washington to Balti- 
more, It even took some time for the 
news media to recognize its value. With 
no immediate financial incentives for 



building additional telegraph circuits, 
Morse's system sat relatively unused for 
some time. 

One of the early events to awaken 
public awareness of the telegraph's 
value occurred somewhat by chance. 
The Democratic National Convention 
happened to be held in Baltimore the 
summer of 1 844, soon after startup of 
the new line. As one might expect, 
there was a lot of interest in Washing- 
ton over what was going on in Balti- 
more. This interest heightened after 
James K, Polk received the Presiden- 
tial nomination, a surprise — followed 
by a bigger one. Silas Wright was 
named the Vice-Presidential nominee, 
and he, upon hearing the news in 
Washington, announced he would 
refuse the nomination, 

Morse sent a telegram to the conven- 
tion in Baltimore with this news, but 
the conventioneers initially refused to 
accept the telegram's authenticity. Af- 
ter the message was in fact verified (by 
railroad dispatch), negotiations began, 
by telegraph, to resolve this nomina- 
tion dilemma. It ended with the nomi- 
nation of, and acceptance by, George 
M Dallas to replace Wright. While 
this incident may seem a minor piece 
of historical trivia, it served to trigger 
a few key people to recognize the 
telegraph's potential. 



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73 Amateur Radio Today • February 1997 39 



Morse viewed the telegraph as a pub- 
lic utility and continued to operate the 
Washington-Baltimore line as a free ser- 
vice for a time, but Congress remained 
uninterested, and the system remained 
primarily a curiosity. At this point, the 
Post Office decided to fund (he Line as 
part of its operations, hut after sustain- 
ing two years of losses (they charged 1/4 
cent per word), the government got out 
of the telegraph business. 

Earlier in Morse's Congressional lob- 
bying days he J d met Francis O. J, Smith, 
then the Congressional Chairman of the 
Commerce Committee. Smith had, at 
that lime, convinced Morse to give him a 
share of the telegraph system in ex- 
change for Smith's peddling his influ- 
ence to help raise money. Smith 
apparently didn't have the influence he 
thought he had because he was able to 
raise only dust, not money, during this 
time. 

Smith had since left public life to be- 
come a promoter of sorts, probably a 
better career choice for him. Still claim- 
ing his pari ownership in Morse's tele- 
graph, however, Smith attempted to 
form a private company to build a line 
between New York and Boston. Unable 
to sell this idea initially, Smith turned to 
building a line from New York to Phila- 
delphia, and by late 1845 had raised 
enough money to begin construction. 

By early 1846, the line had reached 
the Hudson River at Newark. While the 
British had perfected submarine cable 
technology, Smith and company's cable 
was not capable and failed under water. 
This forced temporary use of a river- 
ferry relay in order to get the line 
operational by summer. 

Near the end of July, 1846, the com- 
pany began reporting "profits," thus 
touching off a wave of expansion. It 
should be noted that the actual profit- 
ability was dubious at best, but reporting 
profits sure made stock sales easy! By 
1849, many lines were in and actually 
were making money, partially due to 
news service and railroad business. In 
time, Morse gained a fortune through 
expansions by Western Union and the 
American Telegraph Company, as did 
virtually everyone else associated with 
the telegraph. 

By 1860 most of the Eastern US was 
linked by telegraph lines, and by 1865, 
the US was linked to Ireland and Europe 
by the Trans- Atlantic Cable. 
40 73 Amateur Radio Today ■ February 1 997 



Bibliography 

Briggs, Charles F. and Maverick, 
Augustus, The Story of the Telegraph, 
(New York: Rudd & Carleton, 1858). 

Finkeistein, Joseph, Windows on a 
New World: the Third Industrial Revolu- 
tion, (New York: Greenwood Press, 
1989). 

Jones, Alexander, A Historical Sketch 
of the Electric Telegraph, (New York: G. 
P.Putnam, 1952). 

Prescott, George B., History, Theory, 
and Practice of the Electric Telegraph, 
(Boston: Ticknor and Fields, 1866). 

Reid, James D., The Telegraph in 
America, its Founders, Promoters, and 
Noted Men, (New York: Derby, 1 879). 



Neueh sry die 

Continued from page 3 1 

But what about all those hemophiliacs 
who've been dying of AIDS as a result of 
blood transfusions? It turns out that's lied in 
with a new drug for hemophilia called Factor 
VIIL This is an immuno-suppressive drug, 
so if the patient also is also HIV positive, the 
chances are that a doctor will prescribe 
FDA- approved AZT, and that's the end. 

Maybe you've noticed that none of the 
AIDS establishment's frightening predic- 
tions have materialized. Our hospitals are 
not packed solid with people dying of AIDS* 
The big winners have been the condom 
manufacturers, Burroughs Wellcome Labs 
and their AZT sales, the AIDS support 
groups, and those benefiting from the bil- 
lions of government money that Congress 
has thrown into fruitless research (welfare 
for scientists). 

The Duesberg book is a fascinating 
(if long) detective story, and there is no 
shortage of bad guys put into the spoil ight. 

So then how are the Bioelectrifier and the 
Beck Blood Purifiers pulling so many people 
back from death? I suspect that by passing a 
tiny electrical current through the blood it 
prevents various viruses, microbes, fungi, 
yeasts and parasites from replicating, thus al- 
lowing the immune system to regain enough 
strength to fight off any number of illnesses 
which had gotten the upper hand. Like 
cancers. 

And combined with the damage done to 
people's bodies and immune systems from 
long-term drug use (including nicotine and 
alcohol), there is the mutation of microbes 
which had previously been beaten back with 
antibiotics, in case you haven't read, most of 
our more serious invaders are now antibiotic 
resistant, and the rest are well on their way. 



This onslaught of infectious diseases also 
helps defeat the immune system. If you 
haven't read about it, the current estimates 
are that over 80,000 people died in 1996 in 
hospitals just from diseases contracted in 
those hospitals. That's right, not from the ill- 
nesses which brought them there, but from 
those contracted while there, A hospital is a 
very dangerous place to be, 

I'm not sure whether that 80,000 is in ad- 
dition to, or part of, the 300,000 deaths the 
Ralph Nader researchers attributed yearly to 
hospital errors — mostly errors in medication, 
I suspect it's in addition. 

Dr. Fisher Disagrees 

But not a whole lot. In The Plague Mak- 
ers, Dr. Fisher presents a well -researched 
case targeting not only recreational drug use 
as knocking the immune system down, thus 
allowing the AIDS syndrome to happen, but 
he presents a solid case that the over-use of 
antibiotics by two specific groups, gay men 
and drug users, has significantly contributed 
to the destruction of their immune systems. 
Both gays and intravenous drug users are 
constantly having to fight off infections, 
hence their high use of antibiotics. 

If I had any sort of immune systems re- 
lated illness my first move would be to do 
everything known to get my immune system 
perking at peak efficiency. I'd follow the 
Comby book's raw food diet and change my 
eating habits immediately. I'd get those UVs 
into my eyeballs every day, per Dr t 
Douglass. Td be out there briskly walking 
for several miles a day, rain or shine, I'd 
hyperventilate every hour or so to get more 
oxygen into my system. Pd make sure I was 
drinking at least eight glasses of distilled wa- 
ter a day, And I'd use the Bioelectrifier at 
least an hour or two a day. I would not take 
any prescription drugs (or other drugs, for 
that matter). I would make sure 1 was getting 
vitamins A, C, and E. 

Scientists 

A letter from Albert KE4HUD included a 
newspaper clipping to the effect that the job 
market is tight for scientists. Now, I'ma real 
big fan of science and believe that we have a 
serious need to get our kids interested in 
high-tech careers. But I don't think I've ever 
promoted the idea of anyone going on to be- 
come a scientist. In general, scientists tend to 
be a mile deep and an inch wide in their 
fields, wear lab coats and be super-nerds t 

Looking at it from the career point of 
view, with very few exceptions scientists are 
never going to make much money. Job-wise 
they're heading toward one of two possible 
employment opportunities: working for a 
large corporation, or a university, Neither of 
these is ever likely to pay much except in 
prestige (oh, vanity), 

The odds for making money these days lie- 
in being an entrepreneur, and here a high- 
tech background can be worth zillions. Ask 
coliege dropouts Bill Gates or Steve Jobs. 

Continued on page 43 



Number 41 on your Feedback card 



The Gel Cell Storage Battery 



A great little power supply \ 



Frank Brumbaugh KB4ZGC 

P.O. Box 30, c/o Defendini 

Salinas PR 00751-0030 



The gel cell storage battery is the 
king of batteries both for portable 
operation and for emergency 
backup power in the ham shack. This type 
of battery has a great many advantages 
over other kinds. 

Gel cell batteries are tightly sealed, so 
they can be stored, charged or discharged 
in any position with no danger of elec- 
trolyte leakage or outgassing. No 
maintenance is ever required. 

These batteries are cost-effective, provid- 
ing a high watt-hour per dollar value. They 
are widely available from a number of manu- 
facturers and am low in cost, considering 
their power capability and usual life spans. 

In normal use, the dependable service 
life of gel cell batteries is four to five years 
when used for standby use, and between 
200 and more than 1,000 discharge/re- 
charge cycles as a function of the amount 
of power delivered before recharging. Gel 
cell batteries do not have "memories" such 
as haunt NiCd batteries. 

Gel cells possess a very high energy 
density, resulting in smaller physical size 
for the amount of power they offer. They 
are available in many sizes (from vest- 
pocket to hernia-inducing), and in voltages 
of 2, 4, 6, 1 2, and in some cases 24 and 28 
volts. They can be connected in series for 
higher voltages, and/or in parallel for 
higher load current capacity. 

Gel cell batteries can be charged over a 
temperature range of -20°C to +50°C (4°F to 



P'l>£lflGli:ii:: ^CJjEJ Wl/F 



FtWmVKtEAU 
CauCUjmpucte-- 



SBWunqn 







,-.■:■. 



Fig. 1 . internal construction. 



+122 f T), and can be used to produce power 
fiom 40°C to 60°C (-40T to +140 C F). 

Although it's not recommended, gel cell 
batteries can be discharged much below 
the normal level (in an emergency ), yet re- 
tain the capability of fully recovering when 
recharged. These batteries can also, in pulse 
type service, supply up to 10 times the am- 
pere-hour capacity of the battery for these 
very brief pulse periods. Thus, smaller batter- 
ies can be used when very high peak current 
is required for very short lime periods without 
damage. 

Gel cell batteries are ideal for portable 
operation, especially for low r power sta- 
tions, and most QRP operators in this rap- 
idly growing segment of ham radio use 
these efficient batteries to power their rigs 
when hiking, backpacking or camping. 
These batteries are an obvious choice for 
Field Day, and there tire quite a few bi- 
cycle mobile stations using gel cell 
batteries for power. 

The larger capacity batteries are most de- 
sirable for backup power in the home station, 
and are usually continually floated across the 
+13.8 VDC output of the station power sup- 
ply. This keeps the battery fully charged and 
ready to supply power to the ham station 
should commercial power be lost 

Inside that neat plastic box 

Fig. 1 illustrates the internal construc- 
tion of a typical gel cell storage battery. 
Lead-calcium plates containing a small 
amount of tin are very strong, durable, and 
highly resistant to warping or damage due 
to excessively deep discharging. Tlie electro- 
lyte, a dilute sulfuric acid similar to that used 
in automobile and marine batteries, is locked 
into a gel almost like candle wax, keeping it 
constantly in contact w ilh the plates. 

Separators between positive and negative 
plates are usually made of porous Fiberglas™ 
cloth which is highly resistant to heat and 



| oxidation. This cloth easily absorbs 
electrolyte, further stabilizing the battery. 

Many gel cell batteries contain a pres- 
sure relief valve, as shown in Fig, 1 + This 
comes into play only with excessive gas 
pressure caused by overcharging. It is a 
one-way valve and does not allow ambient 
air to enter the battery. With normal charg- 
ing there will never be an occasion for this 
valve to operate. It is strictly a safety 
device for a worst-case situation. 

The gases produced during charging' — 
oxygen from positive plates and hydrogen 
from negative plates — combine to form 
water, which maintains the water content 
of the electrolyte at the proper level, 
making a truly "maintenance- free" battery. 

The battery case is sealed both mechani- 
cally and with epoxy, plastic or hot seal to 
produce a liquid- and gas-tight container 

Battery capacity-discharging 

Gel cell batteries are available with am- 
pere-hour (Ah) capacities of 0.05 to 100 
Ah, rated for a 20-hour discharge rate. Ca- 
pacity in Ah, always expressed by the 
capital letter "C," is used when calculating 
or expressing the rare of charge or dis- 
charge. The Ah capacity of any battery is 
equivalent to C in all cases. This means 
that the number of Ah (C) discharged at a 
rate of 0.05 C, will discharge the battery 
fully in 20 hours. If the discharge rale is 
higher, for instance doubled to 0.1 C, the 
fully discharged state will be reached in 
just nine hours. Discharge rates are con- 
stant in this example, but would be reason- 
ably accurate for average discharge 
current. These examples apply to all gel 
cell batteries, regardless of terminal 
voltage or Ah capacity. 

As a concrete example, a battery of 2 

Ah (02) will supply 130 mA for 20 

hours, but if called upon to deliver 260 

mA, the battery will be fully discharged in 

73 Amateur Radio Today * February 1 997 41 



nine hours. At the high drain of one 
ampere (C/2). this batiery would he 
discharged in only one hour 20 minutes. 

The fully discharged gel cell baitery 
will produce a per-cell voltage of 1 .75 
volts. For a nominal 12 volt batiery such 
as is used by most hams 7 this is a termi- 
nal voltage of 10.5 volts. Conversely, a 
fully-charged battery will have an open 
circuit voltage of 2.15 volts per cell, or 
12,9 volts tor a 12 volt battery, 

I[ is best, if at all possible, to retrain from 
discharging a batiery below 1.94 volts per 
celt, This amounts to I L64 volts for a 1 2 volt 
battery. Because most ham transceivers either 
quit or operate poorly as the supply voltage 
sinks towards 1 1 volts this is not a hardship, 
and halting discharge cumenl while battery 
voltage is above the liilly discharged stale 
will contribute greatly to overall batiery lite. 

If you're interested in the gory details of 
discharge curves and more technical informa- 
tion thai you'll probably need in this incarna- 
tion, ask a manufacturer for their literature. 

In choosing a gel cell battery for portable 
operation, calculate the current your rig draws 
on receive. ;ind if using CW or SSB, one-hal I 
of the peak current drawn on transmit. 

Assuming ytxi wish to operate a maximum 
of 20 hours before recharging your baiicry, 
your average current drain must not exceed 
0.05 C, Preferably it should be less. 

Because most operating time is spent tun- 
ing and listening on receive and only a small 
amount of time is spent actually transmitting, 
unless yoif re as long-winded as L a simple 
way is to calculate the current in All used dur- 
ing a one-hour period, with perhaps 50 
minutes receive and 10 minutes transmit. 

Calculate 5/6 of receive current drain, 
Then calculate 1/6 of peak transmit current 
drain and divide this by two because the 
intermittent nature of CW and SSB can be 
construed as a 5Wf duty cycle. Then add 
the two final calculated values together. 
The sum is jour average current drain in 
amperes for one hour of operation. 

A real life example: I have a 12 Ah gel 
cell (C=12) which powers a QRP-plus 
transceiver. Receive current is about 0.2 A, 
and half the 1.5 A peak transmit current is 
0/75 A. Taking 5/6 of 0.2 A, which equals 
0.167 A (rounded off), and 1/6 of 0.75 A, 
which equals CI 1 25 A, and adding these 
values together gives a total average 
current drain of 0.292 Ah per hour 

The 20-hour discharge curve shows that 
0.05 C is 0:6 A for litis battery. A simple ratio 
calculation is: ,6 : .05 = .292 : x; .6x = .0146; 
\ = .024. 
42 73 Amateur Radio Today ■ February 1997 





J43I7TB 



D5 



D2 
IN4148 




Z275V/CeU 

DC io Batter? 

float application 



2222 



2.45V/CVII 
Cyclic application 



Fig, 2, Constant cur rent /constant voltage charge circuit. 



Thus, in this case, the average current drain 
is equal to 0,024 C about half of 0.05 C, so 
the 12 Ah battery will allow about 40 hours of 
operation before having id be rechaiged. 

Using a calculator it is much simpler to 
calculate the ratio with the decimal frac- 
tions rather than first converting them to 
powers of 10 as is customary. 

Charging the battery 

A new gel cell battery, although fully 
charged hy the manufacturer, needs a bit of 
exercise to develop its till I capacity. This can 
be accomplished either hy floating the battery 
across the station power supply for a couple 
months. This is simplest if it is a backup 
battery for the home stall on; or has been 
used for a while, undergoing a number 
of charge/discharge cycles. 

A voltage somewhat higher than 2T5 
volts per cell ( 1 2.9 volts for a 12 volt bat- 
tery) must be applied across the battery 
terminals. After discharge, and after charg- 
ing, the terminal voltage may be tempo- 
rarily lower or higher, respectively, but in a 
short while it should stabilize at the 2.15 
voft per cell level. 

The best charging method recommended 
for gel cell batteries is the '"constant voltage, 
constant current" iirrangement. This will en- 
sure maximum battery life and capacity 
while not requiring excessive charging 
time. However, the charging current must 
be so limited that it cannot exceed 0.25 C, 
or I ampere for a 4 Ah battery, for in- 
stance. Wis is most important to prevent 
damage to the battery! 

A large capacity gel cell battery used in 
float service as backup power for the home 
station is never discharged very deeply. 



and recharging requires a tower maximum 
voltage for charging. 

Caution: In all cases the charge current 
must never he allowed to exceed 025 C or 
the Ixitrery could be damaged. 

The recommended float voltage is 2.25 to 
2 J volts per cell, or 13 5 to 13.8 volts for a 
12-voli gel cell battery; This allows the bat- 
tery to be connected permanently across the 
output terminals of the standard 13,8 volt sta- 
tion power supply. If the home station is used 
at least weekly, the standby battery will never 
need charging unless it has been used in an 
emergency to power the station. 

Constant voltage/constant current 
charger 

Fig. 2 illustrates a simple charging cir- 
cuit suitable for the small get cell batter- 
ies normally used for portable operation. 
Because a heat-sinked 317T regulator 
is used, the maximum current is limited 
to one ampere. RS is chosen to provide 
the proper minimum float voltage 
(0.6/R3 = max). 

R2 and R3 are determined by ihe level 
of filtered DC voltage available and the 
maximum cunent (0.25C or lower) to be 
applied to the partially or fully dis- 
charged baitery. They will have to be 
determined empirically. 

The manufacturer of your gel cell bat- 
tery will usually recommend a charging 
circuit for your application if you list your ex- 
pected average and peak current drain and the 
acceptable discharge terminal voltage when 
you write. He not only wants your battery to 
provide efficient service but he also wants to 
sell you a replacement batter) when I he 
lime eventually anives. 



Never shy die 

Continued from page 40 

And the way the world is going, the big 
money is going lo be in high-tech businesses 
for a long time to come. 

It is unfortunate that around 95% (or 
more) of hams memorize the Q&A manuals 
to gel their tickets and the learning process 
stops soon after. Here's a hobby that offers a 
world of learning opportunities, with it being 
fun every inch of the way. But yes, it does 
take some determination and perseverance to 
learn about radio, micro waves, digital com- 
munications, and so on. And yes, our blessed 
school system spends K-12 at a minimum 
doing its best to kill whatever sparks of 
motivation might have been inherited 
genetically. Grumble* 

Fluorides. Again. 

Aie you still drinking lap water? What 
does it take to get you to get a small still and 
start distilling that sewage your city or town 
is providing? You don't need any of the toxic 
metals that come out of your spigots. Worse, 
you surely don't want to put chlorine into 
your body, and the chances are that your 
water system has plenty of that poison. 

But the most damaging of all the water ad* 
ditives are fluorides. Oh, there goes Wayne, 
on some sort of an ecological kick. Oh yeah? 
If you send me an SASE 1*11 send you a copy 
of the results of 30 research lab reports of 
genetic damage caused by fluorides, plus a 
list of 35 published peer-reviewed papers at- 
testing to the genetic damage. These re- 
search reports show clearly that as tittle as 
one pan per million of fluorides in drinking 
water causes measurable genetic defects in 
sperm chromosomes, and that means some 
sort of genetic defect will be passed along to 
your children. And this is not going to be 
helpful. This can mean small or large birth 
defects, none beneficial. And these will, in 
aim, be passed along to your grandchildren. 
That what you want? 

I started out buying gallon bottles of dis- 
tilled water from the drug store, then Pat 
Flannagan mentioned an inexpensive still 
available from Damark. 1 invested in a Gen- 
esis unit, which cost under $200. Works like 
a charm and has paid for itself many times. 

The Dr. Yiamouyiannis book, Fluoride, 
the Aging Factor, which I've reviewed in my 
editorial, and is on my list of books you're 
crazy if you don't read, has the subtitle, 
"How to recognize and avoid the devastating 
effects of fluoride/* 

You*ve read about the decreasing sperm 
count in American men. Well, fluoride in the 
water supply has been shown to do this. It's a 
deadly poison, and helps knock the stuffing 
out of your immune system. 

Do It Yourself! 

Put yourself in my chair — well, walk a 
mile in my moccasins, is the clichd. Suppose 
you were writing an editorial every month. 

Continued on page 55 









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73 Amateur Radio Today * February 1 997 43 



^ 



73 Review 



Number 44 on your Feedback cartf 



The Ten-Tec T-Kit 1 208 
6 Meter Transverter 



Here's a fine introduction to modern kit-building. 





Peter A. Bergman N0BLX 
851 7 Estate Dr SW 
Brainerd MN 56401 

A converter allows your receiver to 
time a band for which it was not 
originally designed. A transverter allows 
your transceiver to receive and transmit on 
a band for which it was not originally de- 
signed, bv subtracting or addine a local os- 
ctllalor frequency— in this case, 36 
megahertz — from or to the displayed fre- 
quency on your transceiver. This gives you 
access to the added band with all of the 
wonderful features already present in your 
expensive HF rig, without spending piles 
of money. 

Suppose your license docs not allow 
you to transmit on the 20 meter kind? This 
is not a problem because you aren't trans- 
mitting on 2(X Instead, you are using your 
20 meter transceiver as a tunable IF stage 
to control the transverter on 6 meters, If 
your HF rig will only transceive from 14 to 
14.35 megahertz that's still not a problem 
since a lot of the action is between 50.0 
and 5035 anyway. Receive coverage up to 
18 MHz lets you monitor the rest of the 6 
meter band. 

If you've never built a kit,,. 

Despite some things you may hear about 
the "Golden Age" of kits, modern kits are 
great, and when you get a kit from an outfit 
like Ten-Tec you can durn near write off 
the cost as tech-school tuition. Add in en- 
tertainment value and the satisfaction of a 
working unit you built yourself and you're 
way ahead. 

Okay, you Lire thinking about ordering 
the T-Kit 1208, but what do you need up 
front? First a 20 meter transceiver capable 
of being adjusted to 5 watts output reliably. 

44 73 Amateur Radio Today * February 1997 






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Photo A. The T~Kit 1208. (Photo by N0BLXJ 



Second, a regulated, well-filtered 12-15 
volt DC power supply capable of about 4 
amps. Third, some kind of 6 meter an- 
tenna. A dipole will do for starters. And, a 
52 ohm dual PL-259 jumper to connect the 
rig to your new transverter. 

Tools? You will need a 1 5 to 35 watt sol- 
dering pencil and thin-diameter rusin cure 
solder. This is a must. Thin-diameter. Rosin 
core. You will also need diagonal cutlers — 
small ones — and needle-nose pliers, ditto, I 
like to keep a pair of locking forceps handy 
They make great heal sinks while soldering 
and are useful in many other ways. According 
to the T-1208 manual the coils can lie wound 
on a .313" X-acto™ knife handle or a clean 
3/8" bolt (that's what I used). The book also 
said you'll need a wire stripper That's what I 
used the X-acto knife for. Alignment tool. Do 

*w- 

not trv usine metal hex winches, screwdriv- 
ers, etc,, as alignment tools. If you don't have 
any yet go to Radio Shack ' M and get their 64- 
2220B set. I also like to keep a sharpened 
dental pick on my workbench. It is very use- 
ful for clearing holes I soldered shut acciden- 
tally; and for unbraiding coax. A 2- or 3-inch 
paintbrush is also useful for cleaning up. 

Test equipment 

You've got to have a voll-ohmmeter for 
this project, and once you get one you'll 
use it for years. There are some inexpen- 
sive digitals available but the better quality 
you start with the happier you will be with 
it. I know that a lot of you have tons of test 
gear but Frn talking to the folks who are 
just getting started in this great hobby. You 
will also have to have an accurate RF 
wattmeter that has a 10 watt scale or slug. If 



you have a cheapie from your CB days 
find someone with a Bird to check it for 
you. Then you can make a correction 
chart lor yours. 

Optional test equipment includes a fre- 
quency counter and an RF signal genera- 
tor. I used my MFJ ,M antenna analyzer for 
both jobs. For a second piece of test 
gear — after the VOM — Fd say that a 249 
or 259 from MFJ is hard to beat. 

Start your kit 

The parts are packed neatly by type in 
separate bags but lef s leave them alone for 
a while and take a look at the instruction 
manual. 

Kit builders seem to fall into two cat- 
egories: those who read and follow the di- 
rections and those who don't, I try to slick 
with the former group. More of my 
projects work that way. 

The 1208 manual contains about 80 
pages; the print is clear and ihc text and 
drawings are concise, A tip of my hat goes 
to Ten-Tec and Dan Onley K4/RA who 
did the writing. 

On Assembly page 48 is an important 
notice about driver transmitter power, AF 
though there are several notices in the 
manual which tell you that the 12t)S was 
designed to use a 5 watt input, it also ex- 
plains that changing the value of R5 will 
allow inputs from ,25 watts to 8 or even 1 
watts. 

It seems to be a fact of life that however 
well the manual is written there are always 
some addendum sheets. Go through them 
carefully and make any needed changes to 
the manual before starting construction. I 



like to run copies of both sides of the ad- 
dendum sheets and cut and paste them in 
the appropriate places in the book. 

Even if you have built kabillions of de- 
vices, and especially if you have not, read 
the theory section. It will help you under- 
stand whaL you are doing and will explain 
why the designers made the decisions they 
did. After that, do the parts inventory. 

Each of the seven assembly phases in- 
cludes a schematic and board layout dia- 
gram of that phase, which is very helpful. 
Phase 1 is preceded by a "dos and don'ts" 
page so that is a good place to start actual 
assembly. Somewhere in your collection 
of baggies is a tiny fertile bead — about the 
size of a mustard seed. Following "do 1" 
install that bead now. That way you won't 
have to worry about where the little rascal 
went later after you have been chasing the 
other parts around for a while. 

The first page of construction is board 
preparation installing "vias," which en- 
sure that the upper and lower ground 
planes are tied together. You will also in- 
stall a few test points and fabricate the test 
plug. A word of warning to the uninitiated: 
The lest plug requires a 1/4 watt 150 ohm 
resistor, not the 3/4 watt you will be 
wanting later. 

Another word of warning: I don't care 
how much money your mother makes or 
who your dad knows or how big your 
brother is, please, never, never carry mol- 
ten solder to the joint on the tip of your sol- 
dering penciL The actual amount of solder 
you'd have to spill on the board to create 
hair-pulling problems is infinitesimal. In- 
stead, heat the joint with the tip of the sol- 
dering pencil and apply the solder to the 
other side of the joint, The solder will melt 
and flow towards the heat and if every- 
thing is nice and clean — as it probably 
is — you will produce a nice, shiny, con- 
ductive joint that will stay that way for 
years. 

Yet another warning: Don't use steel 
wool to wipe off the tip of the soldering 
penciL Sure, it does a great job but you 
will probably have tiny wild hairs of wire 
all over the place. 

If you follow the manual's directions 
you will not get the 3.3 pH inductor mixed 
up with the 3.3 ohm resistor The resistor 
goes over near where you'll install Qll 
later. Handle these small inductors care- 
fully, especially when bending the leads; I 
managed to torque one in half. T-Kit sent 
me a replacement as soon as I called, but 
it's embarrassing and stops production. 



Observe polarity — orientation — on all 
semiconductors and electrolytic capaci- 
tors. Every time. 1 go so far as to install the 
resistors so the color-code reads the same 
way. It helps keep me in the habit of pay- 
ing attention to the orientation and later it 
might help during troubleshooting. Looks 
neater too. When installing disk capacitors I 
try to install them so that I'll be able to read 
the value code easily after the sutrounding 
components have been installed, 

Double-check your work. 

We're having fun now 



Now comes one of the really fun parts- 



the Phase 1 progress test. Unlike the 
"Good Old Days" modern kits like this 
one are designed to be assembled in func- 
tional stages so that each stage can be 
tested with power on. This way, as you 
progress through assembly you know you 
left good stuff behind you. If you skip the 
progress checks and run into problems 
later you'll have to go through the entire 

"Using just an indoor dipole 
antenna, I could hear stations 

all up and down the East 
Coast clear into Canada from 
my home in Minnesota. What 

a gas!" 

device to figure out why. Minimum test 
equipment is an FM broadcast receiver 
tuned to 108 MHz. Got one, right? 

The easiest way I found to perform the 
Phase 2 progress lest was to use a coax 
adapter on my 4-5 watt 2 meter rig. If 
you use a transmitter capable of more 
power make absolutely sure that the 
output is reduced to 5 watts. 

No matter how you feel about 
progress tests, make sure the TR 
circuitry works at this point. 

There are at least two reminders to 
make sure that J2 is securely soldered to 
the top ground plane. Read and heed. 

Follow T-Kit's suggestion about put- 
ting a spacer between the coil and the 
board while soldering. You definitely do 
not want the coil touching the ground 
plane at any point. 

While installing Q15 you may wonder 
why the designer didn't have you do that 
before you soldered all those other parts 
around its space. All the heat you were 
pouring into the board in that area would 



not have done the transistor any good. 
The same is true of the rest of the 
semiconductors on the board. 

When bending the leads on Q15 hold 
the lead with the tip of your needle-nose 
pliers next to the transistor body. Work 
carefully and make sure to bend the 
leads so they all slide easily through the 
mounting holes. If you just sort of line 
them up and pull from the other side of 
the board you may create enough strain 
to break the transistor. 

As luck would have it, when I got to 
the Phase 3 alignment test the band was 
wide open and, using jusi an indoor di- 
pole antenna, I could hear stations all up 
and down the East Coast clear into 
Canada from my home in Minnesota. 
What a gas! 

During these power-on tests and ad- 
justments you will really be glad you 
took your time and got everything to 
work as you went along instead of slap- 
ping things together and hoping for the 
best. 

I deviated a bit from the order in 
which the steps are presented in the 
manual. At one time or another I've 
worked on everything from typewriters 
to bulldozers so I have a feel for how I 
want things to go together. For example, 
I found it easier to rearrange the steps so 
that I worked from the bottom to the top 
when wiring the switches and from left 
to right when wiring the S0239s. 

Make absolutely sure you adjust the 
lengths of the coaxial cables so that they 
can be bundled neatly per the instructions. 
If they are just strung randomly across the 
board all sorts of unpredictable things can 
happen. Also, watch what you arc doing 
when cutting the coax. Somehow I ended 
up with two inches in my hand that needed 
to be in the kit. Fortunately 1 had some in 
the junk box- 
Final alignment 

You had the receiver working, transmit 
bias adjusted and reasonable RF output be- 
fore you installed the board in the case, 
right? If everything is working to your sat- 
isfaction, you are just about finished. You 
might want to find a spot inside the case to 
store the test plug, as I did. 

The fun of building has actually just 
started for you because every time you 
sit down to work you'll know you built it 
yourself. Have fun on the "magic band" 
and 73s, E 

73 Amateur Radio Today • February 1997 45 



Rttv loop 



Number 46 on your Feedback card 



Amateur Radio Teletype 



Marc I. Leavey, M.D., WA3AJR 
P, O. Box 473 
Stevenson MD 21153 



Every February I get this im- 
age, somewhere, of a ham pok- 
ing his head up and looking 
around, like the groundhog on 
February 2nd. Bui unlike the 
groundhog, who is looking for his 
shadow and in that search judg- 
ing the eoming weather, our ama- 
teur buddy is looking for software 
to enable entry into the digital 
universe. 

The questions I receive reflect 
the great diversity of that quest. 
Bob Rushby VE3GLAsent along 
a note saying; 



"I've been active on RTTY for 
some time with a MFJ- 1278. Re- 
cently, I got the chance to buy an 
old HAL ST-6000 for a very good 
price. I*d heard great things about 
how well it works in weak signal 
conditions, so I bought it. 

"My big problem now is what 
is the best terminal emulation to 
use with the ST-6000, The 6000 
has 5-bit Baudot i/o, so normal 
terminal emulations that use 
ASCII aren't much use, I spent 
some time surfing the net to find 
something, but everything I find 
is for more modem devices like 
the MFJ, the KAM, etc." 

Any suggestions? 

Bob, while it may look like you 
have come up against planned 
obsolescence, those of us who 
grew up using World War 11 
equipment 20 or 30 years after the 
fact know that such does not ex- 
ist in amateur radio. That HAL 
demodulator is a fine unit, and 
should do just fine in service once 
again. One program to start with 
is TRTY, which is on the first disk 
of the RTTY Loop Software Col- 
lection, At the end of this column, 
I'll detail how to obtain these 
programs. 

This program is an MS-DOS- 
based RTTY program which can 
also handle packet with a TNC, 
With a plain terminal unit, the 
HAL series being prime ex- 
amples, this program should 
perform admirably to enable both 



ASCII and Baudot communica- 
tion. I would be interested in hear- 
ing how well this works out for 
you on the air. 

Of course, if you have a multi- 
mode controller, there is always 
a question about that one. Greg 
N8TDL writes: 

H have a PK232, What is the 
best software to buy for Windows 
95T 

Along with the XPWare soft- 
ware discussed last month, you 
might take a look at the newest 
version of PaketPeL Now in ver- 
sion 3.2, this program from Chuck 
Harrington runs under Windows 
3.1, 95, and NT; along with OS/ 
2, and virtually all hardware 
TNCs, including the PK-232, 
Chuck passes along some of the 
following features: 

"Point & Click Interface to 
Packet Mailboxes. Mail Window 
passively collects message head- 
ers, then left click to read, right 
to reply! Automatically log mail/ 
traffic sent! Automatically format 
message line length, insert signa- 
ture file, spcllcheck and send! In- 
tegrated 90,000 word Spelling 
Checker- Three integrated text 
editors, Signature/Forms files 
supported. Restartable Yapp and 
text file transfers supported. 

'TNC Settings Editor Dialog 
Box to display/edit your TNCs 
settings! ANSI color graphics and 
sound support. Written in high 



performance C language. Inte- 
grated database listbox to save 
your packet/Internet addresses." 

Fig. 1 shows the display of 
PaketPet, w ith many of the fea- 
tures enabled. You can get a copy 
of the program via the RTTY 
Loop Download Page, or on 
Chuck Harrington's page at: 

http://www.gate jnet/~paketpel/ 

Either way, having obtained 
the shareware version, registra- 
tion to a full package is easy and 
quick. 

When it comes to checking on 
the RTTY Loop Home Page, pay 
attention to the details, please! I 
won't name names, to spare 
anyone embarrassment, but I 
received an E-mail saying: 

"fm not having any luck with 
the web URL that goes like this: 

www:2 + ari k net/ajr/rtty/ 

"Got it from a friend of mine 
and maybe he looked at it with- 
out his glasses on! I'm a born 
again RTTY nut from the old 
days, I am afraid to say. I like the 
smell of my 28 machine running, 
1 am interested in any DOS type 
software for my PC and web 
pages or reflectors on the subject. 

"J guess I need to get off my 
butt and subscribe to 73 again. 
Did for over 20 years and then 
stopped with a job change several 
years ago. I am just now settled 
down and getting back in the 
swing." 

Last things first: Yes, by all 
means, subscribe to 73! There are 
no other amateur magazines on 
the cutting edge, with the fresh- 
ness, or with this column; not to 
mention old Never Say Die! As 
soon as you finish reading this 



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column, rip out thai subscription 
card and mail it in. 

As to the website address, this 
shows just how critical these 
things are. There is a colon in 
there that does not belong. The 
correct address, with the http: 
prefix, is: 

http://www2.arijiet/ajr/rtty/ 

Another thing to note in many 
web addresses is case. With the 
Unix conventions used on the 
Internet, upper and lowercase are 
differem. In this case, "RTTY" 
and "rtty" are different, as would 
be "Software html" and 
"softwaremtml. 11 Be careful, and 
type web addresses exactly as 
given! 

Once you find the page, 
though, you will find a library of 
old lt RTTY Loop" columns, many 
links to a variety of amateur ra- 
dio websites, programs to down- 
load, and a listing of all the 
software available in die RTTY 
Loop Software Collection. Now, 
all of the programs in the collec- 
tion are not online, primarily be- 
cause I do not have enough space 
on my web server to put all 20+ 
Mb of programs up there. 1 do link 
to those available online, else- 
where, though, and have put sev- 
eral up in rotation that many have 
requested. 1 also can E-mail indi- 
vidual programs as requested by 
individuals. But, if you want to 
get the collection, or parts of ii, 
which now numbers over a dozen 
disks, the simplest way is to ei- 
ther download the index listing, 
or, if you are not online, send a 
sel f-addressed, stamped envelope 
to the above address and HI send 
you a copy of the listing. Then, 
decide on which disks you want, 
and send me a 3.5 inch, high den- 
sity blank disk, US $2, and a 
stamped, self-addressed disk 
mailer for each collection desired. 
So, for five of the disks, you 
would send five disks, $10, and a 
mailer or mailers with postage 
and capacity sufficient to return 
the materials to you. 

As well as providing a source 
of programs, 1 look forward to 
your comments, questions, criti- 
cisms and suggestions. Please 
send them to me via snail mail at 
the above address, or electroni- 
cally at ajr@iiri.net, \IarcWA3AJ R 
on AOL, or 75036,2501 on 
CompuServe, 



46 73 Amateur Radio Today * February 1997 



Crrr's corner 



Number 47 on your Feedback card 



Joseph J. CarrK4!PV 

P,0, Box 1099 

Falls Church VA 22041 

Better Ham Software 
Design? Please? 

The only reason I don't refer 
to myself as a computer geek is 
thai I know the definition of geek 
(it's a carnival sideshow per- 
former whose act involves biting 
the heads off small rodents or 
snakes ... look it up, it's in ihe dic- 
tionary). But 1 do like computers 
and computer software. I even 
teach a class in Visual-Basic 4.0 
at our local community college. 

What I don' l like, however, is 
computer software that is poorly 
designed, or which has a poor user 
interface. And that includes a rela- 
tively large percentage of the soft- 
ware written for amateur radio 
and other radio hobbies, 

DOS, by gosh, you're 
kidding, of course 

One pet peeve is MS-DOS soft- 
ware that hasn't been upgraded to 
Windows yet. Several mini- NEC 
based antenna design programs, 
and at least two ionospheric 
propagation programs, on the 
market are DOS software. The 
problem is that DOS software of- 
ten will not run on Windows ma- 
chines. As you add software in 
Windows, it starts taking up space 
in the tower 640 K. of memory 
where DOS resides. If the DOS 
program is larger than the remain- 
ing memory available in the lower 
640K, then it won't run (an "out 
of mem ory" error is generated). 

Fve discussed that problem in 
this column before. The solution 
is to either use a secondary con- 
figuration (as allowed in DOS 
6 + 22) or create your own second- 
ary configuration by messing with 
substitute config.sys files. But 
who wants to go to that bother? I 
want to see an icon on the screen 
that connects me to my radio pro- 
gram. Double-click it and go. 
What J don't want to do is mess 
with multiple configurations of 
my computer. 

Today, the availability of Vi- 
sual Basic and Visual C makes it 



too easy to develop Windows pro- 
grams for there to be any excuse 
for selling DOS products. 

Interface design problems 

Even when people design Win- 
dows-based software for hams 
there is often a profound lack of 
skill demonstrated by the devel- 
oper. One of the first things I no- 
tice is the human computer 
interface (NCI), 1 received one 
product from a small developer 
that I declined to review in this 
column because it was so poorly 
done. Some defects were obvious 
(like the hideous background 



EXIT button. So, when a number 
is entered into the textbox, the 
natural thing for a user to do is 
hit <ENTER> rather than <TAB> 
as he intended. So what happens? 
The computer terminates the 
program. Sighhhhhhh. 

Two errors were made in that 
program interlace: I ) setting fo- 
cus to a control you did not want, 
and 2) not using the <ENTER> 
key to navigate from one input 
textbox to the next. The <TAB> 
key does not automatically spring 
to mind when using the program 
like the <ENTER> key does. 

Another gripe came from a pro- 
gram that was obviously written 
in Visual Basic 4,00 (again, the 
run- lime *.DLL tile was present). 
That program used textboxes to 
display calculated data (which is 
fine). The problem was that the 



/ want to see an icon on the screen that 

connects me to my radio program; I 

don't want to mess with muitipie 

configurations of my computer. " 



color and the fact that he used a 
pastel that did not permit clear 
viewing of the eight-point 
typetbnt selected), but others take 
either a practiced eye or one use 
of the program (then the defects 
became really apparent). 

That program was written in 
Visual Basic 3,00 (I could tell 
because the compressed file 
VRRUN300.DL_ was present on 
the distribution diskette — it's the 
run-time engine for VB 3.0). The 
program asks the user to input 
certain data in textbox format, and 
then ii would calculate some neat 
smoke about antennas for you. 
Wonderful. It even worked. 

But the author of the program 
did not realize that, unless he in- 
tentional ly changes the order, the 
first command button laid down 
on the screen at design time is the 
one that receives focus when the 
program executes. Focus means 
that the button is outlined in 
darker grey, and will respond as 
if the mouse was clicked on it by 
pressing the <ENTER> key on 
the keyboard. If a command but- 
ton receives focus like that, then 
it should be the command button 
that initiates the preferred default 
action ■ Instead, he focused his 



author did not lock the display- 
only textboxes. This means that 
the textboxes could be altered by 
the user even though the program 
did not call for it. In VB 3.00 one 
had to manipulate the Windows 
API to lock textboxes, but in VB 
4,00 It's a simple matter of check- 
ing the Locked property as TRUE 
... so there's no excuse not to lock 
the box. 

I've also seen problems in pro- 
grams that cause the thing to 
bomb out. For example, one pro- 
gram from a source in the UK al- 
lows the user to go forward to the 
next step even if the current step 
is incorrect. This program calcu- 
lated the length of antenna ele- 
ments given certain input 
parameters. One of the parameters 
was frequency of operation (F). 
If a user enters 7 1 50 for the fre- 
quency in kilohertz (a legal entry 
in that program), then the correct 
answer is produced. But if the 
user accidentally enters 71 tO by 
striking the i key rather than 5, 
then the resulting numerical value 
becomes zero when the program 
does its calculations. Guess what 
that does when Fis in the denomi- 
nator? A divide-by-zero error 
terminates the program. 



The correct way to handle that 
situation is to provide a means for 
preventing the user from going 
forward until the correct entry is 
made in each inputbox or textbox 
used for input gathering. Several 
approaches to this problem are 
available, so there's no excuse not 
to do it. 

Also, error-handling code 
should be built into the software 
in order to trap as many errors as 
possible. The program might have 
to terminate gracefully (rather 
than bomb out), or the error might 
be user correctable (like entering 
a valid number for F). Error han- 
dling is pan of good program- 
ming, but seems lacking in much 
ham software, 

User interfaces for programs 
are what the user sees on the 
screen. These should be designed 
according to the UFA principle: 
Usability, Functionality, and Aes- 
thetic. Usability means that the 
user can learn to use the program 
very rapidly. To the maximum 
extent possible, the operation of 
the program should be self-ex- 
planatory. Functionality means 
that everything the user needs is 
available on the screen, or can be 
reached with simple navigation 
through screens and menus. If 
also means that two functional 
items, or bits of inform ation, that 
are needed at the same time 
should be on the same screen. 
Getting lost in the menu structure 
should not be possible. The aes- 
thetics of the interface come dead 
last, but that does not mean that 
they arc unimportant. The screen 
should be pleasing to view by 
most people (and that includes 
using neutral colors), and should 
be well laid out. 

Wherever possible, the stan- 
dard Windows approach to screen 
design should be followed. Have 
you noticed that a lot of Windows 
application programs look and 
operate similarly, even though 
they do completely different 
things? An advantage of follow- 
ing the usual designs is that the 
user finds it easier to intuit how 
the program works. After all, 
when he or she sees File in the 
left-hand corner of the Menu Bar, 
it is obvious what will be found 
there, and those items should al- 
ways work the same as in other 
Windows-based programs. 



73 Amateur Radio Today •February 1997 47 



Color usage 

Color pollution is the best la- 
bel I can think of Tor many pro- 
grams Lvc seen. Color should be 
used wisely and sparingly on a 
screen. Color can reasonably be 
used to divide the .screen into dif- 
ferent task areas or different types 
of data, Bui too manv colors on a 

- 

screen increases the visual search 
time required to figure out what to 
do, and where that function is on 
the semen. Also, research shows 
that extensive use of color works 
better for experienced users of a 
program than for novice users. So 
design according to the intended 
level of the user community. 

Programmers, by the way, 
make lousy testers, Even if they 
are the smartest people around, 
they are also loo close to the 
project and too knowledgeable 
about computers in general to 
make a typical user. If you de- 
velop software for hams or S WLs, 
then have some of them (who are 
not geeks in either sense of the 
word) test it for you. 

Consistency 

Software programs should oper- 
ate not only consistent with other 
Windows programs, and other ap- 
plications of similar type, but they 
should also be internally consistent. 
Internal consistency goes two ways. 

First, the user should see the 
same result from the same action 
every time it is initiated. Further, 
every time a follow-on repeat of an 
action is required i l should be done 
in the same manner as in previous 
attempts (e.g. entering the fre- 
quency should not be done in a 
textbox one time and an inputbox 
the next). 

Second, the system should re- 
spond the same way to user inputs 
every time they are made. In teach- 
ing the Visual Basic class I noticed 
several students who would fail to 
clear variables and certain input 
features, and so would create errors 
because the system thought that 
something else was intended. Com- 
puters are terribly ignorant; they do 
exactly, precisely what you tell 
them to do (not what you intended 
ihem to do, which may be 
different). 

One good approach to design is 
to use what the HCI textbooks call 
forcing functions. These are design 

48 73 Amateur Radio Today * February 1997 



features that prevent the program 
from continuing further until the 
user input error is corrected. Ex- 
amples of forcing functions fall 
into four groups: 

Gagging. Prevent incorrect 
input by using strategies such 
as keyboard lockout or 
numeric-only checkers. 

Warning. Display a message box 
or warning label w r hen an error is 
made. Message boxes should in- 
clude a suitable set of alternative 
actions that correct the error. 

Do Nothing. This strategy 
keeps the program from doing 
anything further until the error is 
corrected. 

Self-Correction. When an error 
is made the program detects and 
corrects the error, relying on de- 
fault values. This may be the most 
dangerous approach because you 
may have to correctly guess 
which defaults are the ones 
intended. 

Mea culpa 

I don't want to hold myself out 
as a supreme expert on software or 
interface design, or somehow bet- 
ter than others, Tve made most of 
these errors myself — but Tvc also 
learned. My software is not perfect, 
by any means, but at least Tve 
learned these lessons ... and 
recommend them to others. 



Conclusion 

Sorry to dump on you folks with 
my pet peeve this month, but it is 
an irritant that I suspect afflicts 
many users of ham radio software 
(indeed, all software). Good design 
will make a product look, feel and 
work belter. A lot more can be said 
about the subject, but Fve used up 
my allotment of space for this time. 
Perhaps sometime in the future we 
will return to it. Perhaps. But if the 
makers of ham radio software get 
the message, then it won't be nec- 
essary. Just remember one thing; 
The amateur in Amateur Radio only 
means we do radio for fun, not for 
money. That docs not imply that 
amateurish products are acceptable 
in our marketplace. Amen? 

Connections... 

I can be reached via snail mail at 
P.O. Box J 099, Falls Church, VA 
2204 L or via Internet E-mail at 
carry @aol com. 



Hrmsrts 



Number 48 on your Feedback card 



Amateur Radio Via Satellites 






Andy MacAUister WA5ZIB 
14714 Knights Way Drive 
Houston TX 77083 



The AMSAT Annual 
Meeting 

The 1996 AMSAT Annual 
Meeting and Space Symposium 
was held November 8- 10 in Tuc- 
son* Arizona. Over 250 satellite 
enthusiasts listened to dozens of 
presentations and visited the Kitt 
Peak National Observatory and 
National Solar Observatory. For 
all participants it was a fantastic 
weekend. With the launch of the 
largest and most complex amateur 
satellite only months away, the 
symposium focus was on the 
siaius of the Phase 3D project. 

Friday 

This year the AMSAT Space 
Symposium began Friday morn- 
ing with a presentation by Dr. 
Helen Reed, Director of the 
ASUSat lab. ASUSat stands for 
the Arizona State University Sat- 
ellite. Work is underway to build 
a 10-pound satellite to be 
launched as a piggyback payload 
on a Pegasus rocket. The satellite 
is designed to carry a GPS (Glo- 
bal Positioning System) receiver, 
an earth-imaging experiment and 
a Mode "J" (2 meters up and 70 
cm down) analog and digital tran- 
sponder system. Launch is sched- 
uled for spring 1997. 

SEDSAT Project Manager 
Dennis Wingo KD4ETA brought 
everyone up to date on the sta- 
tus of the SEDSAT program. 
SEDSAT- 1 is a mierosat-class 
satellite that will be part of 
NASA's Small Expendable 
Deploycr System (SEDS). 
Changes in launch schedules 
have caused delays with this 
hamsat. SEDSAT will carry sev- 
eral scientific and amateur radio 
experiments. The SEDSAT pro- 
gram also has a World Wide 
Web home page at the URL 
(Universal Resources Locator), 
http://seds.lpl.arizona.edu- 

John Franke WA4WDL de- 
scribed a fascinating hardware 



project. John's interest in the 
Russian Tsikada (pronounced 
Cicada, like the insect) naviga- 
tion satellites led to efforts to 
decode their telemetry signals. 
He built a dedicated "black box" 
to decode the \5i) Mil/ FM 
signals from the satellites and 
display the time data. 

Peter Vekinis KC1QF wrote a 
paper and made a presentation de- 
scribing changes to his proposed 
"Picosat System'' of low-earth-or- 
bil amateur satellites, Peter pro- 
poses a constellation of Picosats 
all using VHF and UHF frequen- 
cies. Like the Motorola Iridium 
system of "cellular phone" satel- 
lites, the Picosats are to use inter- 
satellite radio links to extend the 
communications range. 

This year's SAREX (Shuttle 
Amateur Radio Experiment) 
talk by Frank Bauer KA3HDO 
focused on a new program, the 
Amateur Radio International 
Space Station (AR1SS), Due to 
the long-term nature of the pres- 
ence of an in-orbit ham station 
and the multinational use ol the 
equipment, there arc frequency 
coordination issues and opera- 
tional aspects to be considered. 
National groups currently in- 
volved include Canada, France, 
Germany, Great Britain, Italy, 
Japan, Russia and the United 




Photo A. Dr. Tom Clark W3IW! 
discussed many topics, including 
his "Totally Accurate Clock" 
and the problems wilh Mexico 
OSCAR 30. 



States, Goats include organization 
of all amateur radio manned space 
flight efforts, support, mainte- 
nance and upgrade of current Mir 
and Shuttle amateur radio gear, 
and the establishment of a single 
integrated radio system for the In- 
ternational Space Station. 

Assi Friedman 4Z7ABA pro- 
vided the gathering with an up- 
date on iheTeehsat-1 program in 
Israel. The first Techsat satellite 
was destroyed due to a launch 
failure in Russia in 1995, The new 
version of Techsat is similar to the 
first with a few upgrades for bet- 
ter digital store-and-forward op- 
eration. Two have been built. One 
will be launched early this year 
More information about the fam- 
ily of Techsats can be found on 
the Internet at the URL http:// 
www.techniGn.ac.il/~asronen/ 
lechsatA 

Other Friday afternoon 
talks included Gould Smith 
WA4SXM's description of the 
activities between the European 
Space Agency and AM3AT* an 
explanation of "what it takes" to 



set up and calibrate a radio tele- 
scope for SET! (Search for Extra- 
terrestrial Intelligence), a 
reception by Dr. Paul Shuch 
N6TX and a tutorial on spread- 
spectrum techniques by Phil Kam 
KA9Q, Phil also presented mate- 
rial on Saturday concerning 
a high-performance satellite 
modem. 

After dinner the talks contin- 
ued but with a focus on new- 
comer topics. Barry Baines 
WD4ASW got things started 
with a general tutorial, while 
Ken Ernandes N2WWD dis- 
cussed the fundamentals of 
Kcplerian elements. The 
evening concluded around 10 
p.m. with Doug Quagliana 
K.A2UPW and his simple, yet 
effective, mobile low-power sta- 
tion description, Doug brought 
along some of his antennas and 
gear to show the attendees. 

Saturday 

Activities began in earnest at 
8 a.m. AMSAT President Bill 




Photo B. Most symposium attendees went on the Kin Peak tour. This 
12 meter dish at the National Radio Astronomy Observatory has 
been used above 300 GHz. 



Tynan W3XO gave an official 

welcome to the symposium par- 
ticipants, Dick Daniels W4PUJ 
got things started with a Phase 3D 
construction update. The satellite 
is in the final stages of integra- 
tion in the Orlando (Florida) lab. 
Launch is scheduled for April on 



the second Arianc 5 rocket from 
the Kourou, French Guiana, facil- 
ity. All of the major components 
are in place and ready to go, with 
only a few exceptions. Work will 
continue at an accelerated pace to 
get everything ready and tested by 
the end of February. 



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73 Amateur Radio Today • February 1997 49 





w 



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-.- . 




Photo C. The 75 meter dish at Kitt Peak is part of the Very Long 
Baseline Array (VLBA) network of radio telescopes, Those on the 
tour got a close-in look at all of the systems. The dish is used at 
frequencies up to 47 GHz. 



Bclale Garbee N3EUA has been 
working on the Phase 3D GPS 
(Global Positioning System) re- 
ceiver system. The original design 
has been scrapped and two new 
GPS receivers are being provided 
by NASA at the Goddard Space 
Flight Center. The purpose of the 
GPS receivers is to determine the 
viability of using GPS for orbit 
and attitude determination at or- 
bits above the GPS constellation. 

An update on the digital sys- 
tems of Phase 3D was provided 
by Chuck Green N0ADL The 
system is called RUDAK. This 
is a German acronym for 
Renerativer Umsetzerfur Digitale 
Amafeurfimk Kommunikation, This 
roughly translates to Regenerative 
Transponder for Digital Amateur 
Radio Communication. The pro* 
gram has a long history from its 
beginnings over a decade ago in 
Munich, Germany. The latest ver- 
sion will start its operational life 
as an orbiting packet-based digi- 
tal communications system. Later 
in the mission it will be repro- 
grammed tor new and faster digi- 
tal modes. Development for this 
new version of RUDAK has been 
based in Tucson, Arizona, and in- 
cludes many members of TAPR 
(Tucson Amateur Packet Radio 
Corporation). 

A Saturday talk by Dn Tom 
Clark W31 WI (Photo A) dis- 
cussed extremely accurate time 
signals available via the GPS 
(Global Positioning System) sat- 
ellites, Tom's device, called the 
Totally Accurate Clock, provides 
an interface between a small GPS 



receiver and a computer. The re- 
sulting timing signals arc accurate 
to intervals of less than a micro- 
second 

An afternoon presentation by 
Ed Krome KA9LNV covered a 
Phase 3D-related topic. Ed pre- 
sented 'The View From Below: 
Thoughts on Phase 3D Ground 
Station Requirements." Due to 
the many ham bands covered by 
Phase 3D, the nature of the final 
orbit and the power output of the 
satellite's transmitters, working 
Phase 3D from the ground will be 
quite different from current sat- 
ellites. Ed proposed the use of 
small microwave dishes with 
multiple concentric or offset feeds 
and small VHP/UHF yagis 
all mounted on a single 
boom. The use of mast-mounted 
downconverters and trans- 
mitconverters was proposed for 
modifying current ground-based sys- 
tems to operate new modes of 
Phase 3D. 

Saturday was not all Phase 
3D. Past AMSAT board mem* 
her Harry Yoneda JA1ANG 
provided an update on the op- 
eration of Fuji-OSCAR-29. 
AMSAT President Bill Tynan 
W3XO presented some 
thoughts on possible projects 
| beyond Phase 3D. AMSAT 
Vice President of International 
Affairs Ray Soifcr W2RS gave 
his observations on the "Ama- 
teur Satellite Service in 1996," 
while Richard Limebear 
G3RWL expressed his con- 
cern for the future of amateur 
satellites. 



Prior to the banquet, Bill Tynan 
hosted the annual AMSAT 
meeting with members of the 
Board of Directors and AMSAT 
officers on stage. This is always 
a great opportunity for AMSAT 
members to ask questions of a 
group that is only together in one 
place once a year. 

Following the meeting and 
some time out for ''attitude adjust- 
ment/ 7 the yearly banquet, awards 
presentation and prize drawing 
were held. The banquet speaker 
was Darrel Emerson AA7FV. 
Darrel is in charge of the 12 meter 
radio telescope on Kitt Peak near 
Tucson. His discussion of radio 
astronomy and the pioneers that 
opened up this fascinating field 
was quite thought- provoking. It 
was also a preparation for the in- 
credible tour scheduled for 
Sunday. 

At the awards presentation 
many AMSAT supporters were 
honored and a special plaque was 
presented to the American Radio 
Relay League for their work to 
provide over $500,000 for the 
Phase 3D program. After the 
awards, prizes finished the 
evening. They ranged from 
books, T-shirts and maps to gear 
from SSB Electronics, an antenna 
system from Larsen, a mobile 
transceiver from Kenwood and an 
all-mode VHF/UHF transceiver 
from ICOM. 

Sunday 

Following the Field Opera- 
tions Breakfast at 7:30 a.m., ev- 
eryone took off for Kitt Peak in 
chartered buses. For satellite en- 
thusiasts il*s hard to imagine 
anything more exciting than the 
close-up tour of the Phase 3D 
facility that occurred at the 1995 
AMSAT Space Symposium. Kitt 
Peak may not have any satellites 
to look at, but the technology, 
electronics and giant dishes of 
the National Radio Astronomy 
Observatory were incredibly 
impressive. The AMSAT Board 
of Directors meeting was post- 
poned so that everyone could 
attend. 

The tour included the 12 
meter radio telescope (good up 
to 300 GHz) and the 75 meter 
radio telescope (good up to 47 
GHz). The 75 meter dish is part 
of a global network of identical 






dishes that are used together lo 
create the VLBA (Very Long 
Baseline Array). Tom Clark 
W3IW1 provided details about 
the coordination of observations 
between locations, 

A walk through of the 1 2 meter 
dish control room and a "hard- 
hat" climb through the feedline 
room at the back of the 75 meter 
dish provided real perspective to 
the show. The clear air, high alti- 
tude and incredible view in all 
directions are hard to describe 
when experienced from the sup- 
port structure of a giant radio 
telescope. 

The lour didn't end with the ra- 
dio telescopes. The Symposium 
attendees also got a chance to 
view the Mayall 4 meter optical 
telescope, the 2. 1 meter telescope 
and the incredible National Solar 
Observatory. The solar "tele- 
scope" is 500 feet long, mostly 
underground, and looks like a gi- 
ant temple built by an ancient or 
alien civilization. It is used to study 
the complex surface motions of the 
sun in order to gain a better under- 
standing of the interior 

After the all-day tour, Bill 
Tynan W3XO started the 
AMSAT Board of Directors' 
meeting, which lasted through 
mid-Monday with a few breaks 
for food and sleep. The agenda 
covered many items, including 
publications, SAREX, ARISS, 
long-range planning, new satel- 
lites and the budget. The Phase 
3D program was again the main 
topic. AMSAT still has a signifi- 
cant challenge ahead to pay its 
part of Phase 3D and maintain 
other activities. Launch date 
slippages cost money, just to 
keep testing and other contract 
work going until launch. 

Toronto, Canada, is the site for 
the 1997 meeting. It is sure to be 
a fascinating event since Phase- 
3D will be in orbit by then. Watch 
for more information on the 
AMSAT Web page at bttp:// 
www.amsat.org. 

Copies of the "Proceedings" 
of the symposium are avail- 
able from AMSAT or the 
ARRL, The softcover book is 
8 l/2 r ' by 11", 232 pages. It's 
well worth the cover price of 
SI 2. AMSAT can be contacted 
at 1-301-589-6062 for details 
on shipping charges. 



50 73 Amateur Radio Today • February 1997 



Number 5f on your Feedback csrti 



Hrm to Hrm 



Dave Milter NZ9E 
7462 Lawler Avenue 
NitesIL 60714-3108 

Just a reminder to keep the "Ham 
To Ham" column in mind whenever 
you run into an interesting solution 
to a problem in your pursuit of ama- 
teur radio. I need lots mora input to 
keep the column lively and inter- 
esting. Any idea, suggestion, tip or 
solution is fair game, as long as it 
has applications to the hobbies of 
electronics and ham radio. We've 
all discovered unique approaches 
and resolutions to our common 
problems, and "Ham To Ham" is 
the ready forum for sharing them 
with other 73 readers. Just jot down 
your ideas and send them to the 
address above; 1 11 let you know if 
I can use them and roughly when 
they'll appear, include an informal 
sketch if you feel that would help 
explain your suggestion, and a short 
text (handwritten or typed), and I'll 
take it from there. 1*11 put it into the 
tone of wording thai V ve been us- 
ing for the column and redraw the 
illustration if needed, so don't let 
formality hold you back. Now to 
this month's ideas. 



a 



By merely typing 
Wr, ■- on an infected 

disk, you can 
spread the virus to 

your hard driver 

Viral protection 

From Terry Huckleberry 
N5FYI: Protecting your computer 
from an insidious viral attack: 
"Most vims infections occur as a 
result of people exchanging dis- 
kettes. The best mainline protection 
against infection is therefore the 
pre-scneening of any and all incom- 
ing disks. Even before reading the 
disk's directory! 

"Most viruses also lie dormant 
for a period of time, before self-ac- 
tivating and causing any critical 
damage to your system. During its 
dormant stage, however, the virus 
can be reproducing, spreading itself 
into other areas of your system, 



undetected. The sinister virus pro- 
grammers aren't looking for instant 
destruction, but rather for the wide* 
spread latent destruction made pos- 
sible by wailing patiently to attack. 
This is one of the features that can 
make the more sophisticated 
viruses so devastating. Early dis- 
covery and elimination ends the 
virus's life-cycle. 

*The solution? Virus-scan every- 
thing that you import into your 
computer before doing anything 
with that program. Scan all outside 
floppies before even reading their 
directories, A friend of mine re- 
cently downloaded a virus scanner 
and found that there was a virus in 
the zip File of the virus scanner it- 
self! Scan each installation of ev- 
ery program or data file; in most 
cases, you can stop the viral spread 
beyond the initial file that contains 
the disease if you're consistent with 
this policy, 

"Any virus detected should be 
considered dangerous! 

"A further warning: Even fac- 
tory-sealed program disks can't 
be considered absolutely virus- 
free, and due to the way in which 
files are often packaged, a pro- 
gram loaded directly from a fac- 
tory-boxed disk can't usually be 
fully virus-scanned until it's in- 
stalled on your system. The best 
policy then is to re-scan for vi- 
ruses after each installation (and 
before actually running the pro- 
gram) on any newly installed 
outside programs. This may 
seem extreme to some, but so is 
the damage that can occur from 
an infected outside disk." 

Moderator's note: Terry 
brings up some important points , 
It's a shame that we even have 
to worry about things like this, 
hut we've all heard the horror 
stones of intentional viruses. As 
programming techniques and 
packaging alternatives become 
more sophisticated, it may be 
less likely that viruses will be 
able to spread as readily as they 
do today, but until that time, its 
best to stick with the safest ap- 
proach. There are numerous vi- 
rus scanning programs available 
today, and Terry mentioned that 



he s had good results with F-Prof 
and Thunderbyte G lints scanners, 
to name just two. Additionally, 
make sure that your anti-virus pro- 
gram is a recently updated version: 
as the anti-virus scanners become 
more adept at ferreting out the cul- 
prits, the virus programmers often 
counter with sneafderviruses, remi- 
niscent of the old nuclear "Cold 
War" days! 

From Rich Measures AG6K: 

Some tips for dispelling the equal- 
izing resistor myth, and straight- 
ening out some of the confusion 
surrounding the use of equalizing 
resistors and capacitors across 
high voltage diodes: "In days of 
yore, when silicon diodes were 
first introduced to the consumer 
electronics market, the absolute 
'need* for equalizing resistors and 
equalizing capacitors across the 
newly discovered critters was ad- 
mitted by virtually everyone. To- 
day, things are a lot different. 
Silicon rectifier manufacturing 
technology has come a long way, 
and inherent similarity from de- 
vice to device is the norm, not the 



exception. So are equalizing re- 
sistors and equalizing capacitors 
across the current offering of sili- 
con rectifiers really needed now? 
"No. In fact t they can actually 
cause problems of their own in the 
scries high-voltage power supply 
circuits found in most amateur HF 
linear amplifiers. Here's why: The 
little 1/2 watt carbon composition 
resistors normally used in this ser- 
vice were never designed to 
handle more than about 350 volts 
maximum DC across their rela- 
tively small carbon elements; 
most high voltage diode stacks 
used in modem linear* are ex- 
pected to carry twice that voltage* 
or more, safely. So, over time, in- 
ternal stresses within these 350 
volt resistors can eventually cause 
one or more to break down— usu- 
ally by decreasing gradually in 
value — and then the domino ef- 
fect takes over. In short, one or 
more resistors fail, putting that 
much more strain on the rest, and 
eventually causing catastrophic 
failure of otherwise perfectly 
good parts in a series circuit such 
as the one described. 



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73 Amateur Radio Today * February 1997 51 



"Instead of using equalizing re- 
sistors and capacitors these days, 
just make sure thai the total PIV 
of the entire silicon rectifier slack 
will handle the total peak voltage 
to be expected, with substantial 
safely margin to spare* and leave 
it at that. 

"One factor lhai should be rec- 
ognized, however, is thai all of ihe 
rectifiers in a series-connected 
circuit should have simitar junc- 
tion capacitances — using the 
same type number rectifiers will 
normally assure this, If they're 
not equal, then the re verse- volt- 
age across the lower capacitance 
rectifiers will tend lo be exces- 
sive, because smaller capacitors 
charge faster than bigger capaci- 
tors. It's a good idea, therefore, if 
rectifier lypes must be mixed in a 
series circuit, to equalize with 
disc capacitors. If some 6 amp 
rectifiers are used as replacements 
in a circuit using I amp devices — 
assuming that's all that the 
repairperson has on hand— then 
a .01 pFdisc cap across each de- 
vice may help, but only because 
of the wide variation between 
those 1 amp and 6 amp rectifier 
natural junction capacitances. 
Again, there's no need to add 
'equalizing* caps and resistors in 
a series circuit having all the same 
pail numbers — and it can even do 
harm. 

"Here's one thing of interest 
that I once ran into, though it's not 
by any means a common problem. 
I encountered a production am of 
silicon rectifiers that apparently 
had poor spot-welds inside the 
rectifier casing itself. Internal 
heating and cooling eventually 
caused Lhese welds to break* com- 
pletely opening the rectifier from 
current flow — not a healthy con* 
dition in a series HV circuit, If one 
of the capacitors in the circuit is 
not being charged by its respec- 
tive rectifier, then reverse current 
can be forced though it and the 
results are noisv and messv. If vou 
ever run into just one open sili- 
con rectifier in a series HV cir- 
cuit, don't take chances. For the 
10 cent price of a rectifier today, 
replace all of them, just in case it 
was the product of a poor manu- 
facturing run. The normal failure 
mode for these devices is a dead 
short, caused by too much 
forward or reverse current, not 



an open, Be forewarned. Be 
suspicious." 

Power supply tips 

From Peter Albright 
AA2AD: Some tips and tech- 
niques on practical linear power 
supply troubleshooting. "'Linear 
(not 'switching ) power supplies 
are sometimes the easiest of the 
many circuits to be found in ham 
transceivers to troubleshoot, and 
they're also often the most prone 
to failure due to the demands im- 
posed upon them. Quite often, 
diagnosis of other circuit failures 
can be traced to incorrectly oper- 
ating power supply circuitry* so 
this part of the chain should al- 
ways be checked for proper oper- 
ating parameters before going 
into the more complex circuitry. 

'Most power supplies can be 
thought of as containing five ba- 
sic blocks; 1 ) the input interface 
block (the input line cord, protec- 
tion circuit, power transformer, 
etc); 2) the rectifier block (where 
AC is converted into pulsating 
DC); 3) the filter block (where the 
pulsating DC is converted into 
smooth DC): 4) the regulator 
block (where output voltage sta- 
bility is determined): and 5.) the 
output interface block (where cur- 
rent limiting resistors and/or wires 
and PC board traces carry the sup- 
ply voltage to other stages of the 
transceiver). By thinking of the 
power supply in terms of individual 
blocks, it's often easier to isolate 
problems in the power supply us- 
ing the logical steps of elimination. 

'The first analysis of any sus- 
pected power supply problem can 
begin with the unites cover in place, 
Is the line cord in good condition, 
is the fuse intact (if accessible from 
the outside), what (if anything) un- 
usual was noticed at the moment of 
failure, was anything spilled on the 
unit or did a voltage surge or light- 
ning strike occur? Was ihcre am 
smoke or perhaps unusual noise 
associated wiih the failure? All of 
these 'external* clues can help lead 
us to ihe eventual solution to the 
problem. Always look fust for the 
obvious, it can save countless hours 
of needless troubleshooting time 
(an intermittent AC tine cord or fuse 
holder, for instance). 

**Onee the cover is actually 
removed, leave the equipment 
unplugged and begin your visual 



inspection. Do any parts appear 
to be overheated? The trans- 
former should be carefully in- 
spected for signs of excessive heat 
(and odor associated with hot var- 
nish), resistors should not appear 
darkened or discolored, electrolytic 
capacitors should not be leaking or 
bulging and all wiring or printed- 
circuit board traces should be free 
of signs of excessive heat or ther- 
mal stress. Do the solder connec- 
tions look clean and bright and are 
component leads clipped off so that 
they won't short lo adjacent solder 
pads? Checking the power supply 
circuitry visually can save a great 
deal of time and effort if done sys- 
tematically and wiih care. Anything 
at all that 'appears* suspect should 

be removed and checked (or 
substituted) before going on. 

"Now we're ready forihe power- 
on lest, but be very careful — most 
power supply circuits can have le- 
thal voltages present when operat- 
ing, at least in the area of the 
primary fuse and the AC line cir- 
cuitry. Always know where these 
points are before putting your hand 
inside of the chassis and proceed- 
ing with any voltage tests. 

"Having a schematic diagram 
can be a big help at this point. 
Check the diagram and locate the 
output regulator or regulators, then 
measure their input and output volt- 
ages with respect to ground. If you 
don't find the expected voltages 
(which are generally indicated on 
the diagram), then the problem 
could be in either direction, Le, ei- 
ther the correct voltage isn't being 
applied to the regulator's input, or 
the regulator is bad or the output 
voltage is being dragged down by 
a highcr-than-usual current demand 
somewhere in the circuilry that's 
being fed by that regulator If you 
can open a link to that subsequent 
circuitry (by removing one end of 
a resistor, a steering diode or sim- 
ply removing a wire), then you can 
eliminate the circuitry being sup- 
plied power as the source of the 
problem. 

"If you don* i have a schematic 
diagram or other technical informa- 
tion, all isn't lost; often you can as- 
sume that the normal voltage 
reading obtained with a voltmeter 
across each of the large electrolytic 
filter capacitors will be about SOfr 
of the voltage marked on the capaci- 
tors. It's not exact, but often enou eh 



to determine proper operation at 
leasu Many times, voltage regula- 
tor ICs will have their regulated 
output voltage coded into the part 
number, such as a 7805 is a 5 volt 
regulator and a 7812 is a 12 volt 
device. Again, by working back 
through the various blocks, you can 
often tell if a reading 'seems* nor- 
mal or if it's 'out of the ballpark* 
altogether. Experience helps, but 
experience is only gained through 
actual troubleshooting practice. 
Chances are, you'll do better than 
you think you're able to do, just by 
using these logical steps and think- 
ing of the circuits in terms of the 
five basic blocks mentioned earlier. 
Why not give it a try?" 

Moderator s note: Pete does a 
good job of outlining some time- 
honored procedures for power sup- 
ply troubleshooting. Knowing the 
normal failure modes of compo- 
nents is also helpful when attack- 
ing power supply problems; here 
are a few; 

Fuses always open (badly black- 
ened fuses usually mean a high~cur~ 
rent short). Power diodes normally 
short (smaller signal diodes t LEDs 
and small letters usually open). 
Resistors normally open or change 
value with overheating. Transform- 
ers can open or overlapping turns 
can short internally (some trans- 
formers have internal thermal pro- 
tectors that can open). Dry 
capacitors (such as disk capacitors) 
normally short or become very low- 
value resistors. Electrolytic capaci- 
tors can leak, dry out and lose their 
capacity- to store energy. They van 
also short, often with dramatic re- 
sults. Voltage regulator fCs can 
open, short or change their output 
parameters (they can also oscillate 
at times}. 

Note that these are the normally 
"expected" failure modes of com- 
ponents in power supply service* 
others are also possible. / Ve seen 
power transformers go up in smoke, 
high voltage electrolytics explode, 
regulator ICs blow apart into tiny 
pieces t resistors sputter and smol- 
der, plastic insulation on wires com- 
pletely melt away and fuses weld 
themselves inside of their holders. 
Power supplies or their feedlines 
are generally where these sorts of 
things happen, so any suspect 
power supply component should 
be considered for replacenwnt as a 
precaution. 



52 73 Amateur Radio Today * February 1997 



Cable IDs 

From Dave Hyman KB0ONF: 

'Time to stari saving those little 
square plastic closures often found 
on plastic bread bags; they make 
nice cable identification rags. A 
drop of lacquer thinner will remove 
any printed matter on the tags, and 
a sharp black permanent marker 
will allow you to write your own 
information in its place. They fit 
nicely on most sizes of cabling 
found around the average ham 
shack, but the hole can also be en- 
larged a bit with a hobby knife if 
needed. If the tag refuses to stay on 
a particular cable, try putting a small 
piece of good quality transparent 
tape across its split edge/* 

Moderator's note: Nice idea, 
Dave Does anyone hove any other 
favorite cable-marker schemes? 
Here's something to complement 
any cable marking idea: Instead of 
trying to put all of the information 
needed on the tag itself, use a 
"cable schedule. f ' It s simply a form 
{make up one and photocopy a 
bunch of them) that shows a cable s 
number (such as #100)> the type of 
cable (RG-8X coax), the source 
(FT-10QQMP Antenna Jack), irs 
destination (Linear Amp Input 
Jack) and its purpose (RF feed from 
transceiver to linear), A sheet of 
standard (8-1/2 x 11 ") paper will 
easily hold the information needed 
on 20 or so cables when oriented 
in the II " (landscape) direction. A 
cable schedule allows you to put 
just a cable number on each end of 
a cable, rather than trying to de- 
scribe what the cable's function is 
on a rather small tag ...that's all 
done on the schedule form sheet 
instead. The cable schedule form 
gives more information than would 
ever be possible otherwise, and 
permits you to change the function 
of a cable when redesigning your 
station— only the entry in the cable 
schedule form need be changed. We 
used cable schedules extensively in 
broadcast installations, consider- 
ing the cables more or less perma- 
nent, and only their functions as 
changing. Do it in pencil. It '$ logi- 
cal and flexible once you 've become 
used to it. but you do have to keep 
it up to date if it's to be of value. 

Cleaning up after a hamfest 

From Mark MarhuLin 
KE6JJR: "You can often make 



those tiot-so-attractive 'hamfest 
specials 1 come back to appearing 
close to new, by simply mixing 
some hydrogen peroxide and wa- 
ter as a cleaning agent. Hydrogen 
peroxide is inexpensive, and can be 
obtained at any drug store, but it 
does a nice job of cleaning grit, 
grime and tobacco smoke stains 
from a piece of equipment It also 
kills bacteria and breaks up organic 
matter — that might have been an 
unexpected bonus — with its bub- 
bling or cavitation action. The ex- 
act proportions can be arrived at 
experimentally* but a 50-50 blend 
is a good place to start, since the 
typical consumer-available hydro- 
gen peroxide is usually only about 
3% strength. Give it a try and see 
how it works for you. By the way, 
it's also used as a bleaching agent, 
so avoid getting any on your 
clothing," 

"Mark's tip is 

another reason 

why hydrogen 

peroxide may 

deserve a reserved 

spot on your 

bench. " 

Moderator's note: Fve kepi a 
hoi tie of hydrogen peroxide on my 
workbench for years for applying 
to small cuts and scrapes on my 
hands, because of its anti-bacte- 
rial properties; an MD friend told 
me about it long ago. Mark's tip 
is another reason why hydrogen 
peroxide may deserve a reserved 
spot on your bench. Vve also 
found Dow 17A foaming bathroom 
cleaner (available at supermar- 
kets) good for cleaning particu- 
larly grimy equipment panels and 
cases* It too has a cavitation 
action that breaks away stubborn 
collected material, hut rest it 
first on an out-of-the-way spot to 
make sure that it's compatible 
with the pain t and silk- screen- 
ing used on your rig— you don't 
want to "clean away" important 
informationl 

Murphy's Corollary: Explaining 
something so clearly, and in such 
detail, that no one could possibly 
misunderstand it, will inevitably 
guarantee that someone wilL 



That wraps up this month's col- 
umn; does anyone have any ideas 
on "different* 1 uses for common 
items such as K9PKM gave us? 
Send them, or any other ham-re- 
lated tips, ideas, suggestions or 
shortcuts to me at the address in the 
masthead, and Til share them with 
the rest of 73 T s readers. That's our 
purpose, sharing practical ideas 
Ham To Ham. 

Many thanks to this month's con- 
tributors, including; 

Terry Huckleberry N5FYI 
3409 Osage Road 
GatesvilleTX 76528-1846 

Richard L. Measures AG6K 
6455 La Curnbre Road 
Somis C A 93066 

Peter Albright AA2AD 
28 E. Summit Street 
LakewoodNY 14750 

David L. Hyman KB0ONF 
1455 Edgcumbe Road 
St. Paul MN 55 1 1 6 

MarkMarholinKE6JJR 
15 88 Four Oak Circle 
San Jose CA 951 31 

Note: The ideas and suggestions 
contributed to this column by its 
readers have not necessarily been 
tested by the column's moderator 
nor by the staff of 73, and thus no 
guarantee of operational success is 
implied. Always use your own best 
judgment before modifying any 
electronic item from the original 
equipment manufacturer's specifi- 
cations. No responsibility is implied 
by the moderator or 73 for any 
equipment damage or malfunction 
resulting from information supplied 
in this column. 

Please send all correspondence 
relating to this column to 73 f s Ham 
To Ham column, c/o Dave Miller 
NZ9R 7462 Lawler Avenue, Miles 
IL 607 14-3 108, USA, All contribu- 
tions used in this column will be 
reimbursed by a contributor's fee 
of § 1 0, which includes its exclusive 
use by 73. We will attempt to 
respond to all legitimate contribu- 
tors" ideas in a timely manner, but 
be sure to send all specific questions 
on any particular tip to the origina- 
tor of the idea, not to this column's 
moderator nor to 73. E& 

73 Amateur 



QRH . . . 

Continued from page 8 

Interesting Web 
Sites 

If you have Internet access, and are 
interested in looking up various 
callsign information, you may find the 
following web sites useful: 

http://www.webbuild.com/~ki4hn/ 
vanity.htm 

This site contains the latest infor- 
mation on the issue of "vanity" 
callsigns. There are files which include 
listing of al! vanity callsigns issued on 
each day, since about the July time 
frame. There are also files which con- 
tain a collection of all the callsigns 
issued by call area. The files are up- 
dated daily. If you are interested 
in following the vanity callsign pro- 
gram, this is a good place to look for 
information. 

http://www.ual redu/^ham radio/ 
calJsign.html 

This Is a page at the University of 
Arkansas. It has an up-to-date copy 
of the FCC database. The information 
at this site is usually only a day older 
than the information at Gettysburg. 

Essentially, this site can serve as 
an equivalent of the US Callback, Ad- 
ditionally, it has some search capa- 
bilities. For example, if you want to 
look for all the hams with the name 
of "HigginbothanV the search engine 
will show there are 48 in the FCC da- 
tabase. Or, if you want to look at all 
the hams in North Attleboro, the 
search engine will show there are 74. 
It shows the number of hams in 
Attleboro to be 87 r including one 
with a British callsign and two with 
Japanese callsigns. 

Take a peek at either of these web 
sites if you happen to be "surfing the 
net": 

www.lantz,com/cbs 

This URL is a pointer to a site that 
tracks recent changes. It has a pointer 
to a US file, and it has pointers to files 
for each state it doesn't, however, 
seem to record recent vanity callsign 
changes. 

www.arri.org/fcc/fccld.html 

This URL is a pointer to a data- 
base of the recent FCC database 
changes. It is said to cover about a 
six-week period. You can scan this 
using any call that might have 
changed in the six-week period. You 
can query using either the u old" call 
or the "new" call. This seems to be 
about the best place to look for 'very 
recent changes." 

By Dick WS1H t in T/ie Chirp 'n' 
Click/' December 1996 r the official 
newsletter of the Sturdy Memorial 
Hospital ARC. M 

Radio Today * February 1997 53 



Number 54 on your Fevtioavk card 



HSK KttBOOM 



MichaelJ. GeierKBIUM 
c/o 73 Magazine 
70 Route 202 North 
Peterborough NH 03458 



Crunch, Crunch! 



you've spent much time 
around radio gear, you know it 
can have its share of problems, 
just like all electronic things. 
Some of the issues are similar or 
identical to what you find in 
camcorders, stereos and the like. 
Some, though, are peculiar to RE 
and are common enough that we 
have names for them. One of the 
most often heard complaints is 
that a radio has the "crunchies." 
What the heck is that? 

A "crunchy" radio is one that 
transmits a characteristic sound of 
teeth crunching. OK, it's really 
just a crackling noise, but it does 
sound like the transmitting opera- 
tor is munching on popcorn while 
carrying on a QSO. Of course, 
perhaps he or she is doing exactly 
that! Such an obvious explanation 
aside, it's safe to assume the ra- 
dio itself is the source of the 
crunching noise, and some rem- 
edy must be applied. So: What 
causes crunching noises in a 
transmitter? 

Pick one 

Unfortunately, there's no single 
cause. While it might seem intui- 
tive that crunching sounds are 
generated by bad connections 
(and many are), the kinds and lo- 
cations of those connections can 
be surprisingly difficult to pin 
down. Also, some crunchies are 
caused by effects not related to 
bad connections at all! So, let's 
take a look at the crunchies and 
how you can get rid of them. 

Is it me? 

Before you go trying to solve 
your rig's crunching problems, be 
sure it really is your radio that's 
doing the crunching! Repeaters, 
themselves, are quite prone to the 
crunchies, and many operators 



Your Tech Answer Man 

think their radios are the problem 
when the real trouble is up on a 
hill, miles away. Often, the lis- 
tener reporting the sound is no 
help: it's amazing how many 
people forget they're operating 
through repeaters and attribute 
everything they hear to the other 
op's rig. 

Easy crunch 

Some cases of the crunchies are 
easily solved. If your microphone 
cable has a broken wire inside, it 
can still work because the two 
ends are touching each other. As 
you move it around, though, it Ml 
cause massive crunchies. I've 
heard plenty of mobile rigs doing 
that, and have had a few myself. 
Usually, the cable damage occurs 



from bad crunchies to making 
the radio try to transmit and re- 
ceive at the same time! it pays to 
carefully squeeze the FIT while 
listening to another rig. 

The other end 

An often-overlooked, but com- 
mon, cause of crunchies is bad an- 
tenna connections, 1 remember 
one case in which the mobile rig's 
SO-239 connector had accumu- 
lated greenish gunk inside, pre- 
sumably because the radio was on 
the floor of the car and had seen 
plenty of rain, snow and moisture. 
The result was poor contact with 
the antenna plug, and a bad case 
of the oF crunchies. That kind of 
antenna problem can wreck the 
final amp module, too, because 
the SWR goes up and down 
quickly and constantly. Luckily, 
no damage was done. 

Naturally, bad connections to 
the power supply can cause 
crunchies. Although the problem 



Always check those BNCs; it makes 
sense to expect trouble there. " 



right near the plug, although 
sometimes it's at the mike itself. 
Often, you can just cut the plug 
off and reattach it after snipping 
off an inch or so of cable. Before 
you do, though, wiggle the cable 
while transmitting and listening 
on another rig, to be sure you've 
found the bad spot. 

Another common cause of 
crunchies is the PTT switch. 
Older rigs used relays (them- 
selves a serious crunchiness of- 
fender) to switch between 
transmit and receive. The relay 
didn't care about the exact resis- 
tance of the PTT switch, as long 
as it was low enough to provide 
sufficient current for pulling in 
the relay, With today's solid-state 
switching, it's another story. In 
most of today 's rigs, the PTT line 
is an input to the microprocessor. 
Like the relay, the micro doesn't 
really care whether the switch has 
some resistance. However, that 
line often also docs some other 
things, and, when the switch's 
resistance goes up, it can make the 
radio go haywire. I've seen flaky 
PTT switches cause everything 



can be at a terminal or even a fuse, 
it doesn't seem to happen much 
in mobiles and bases. HT battery 
tracks, on the other hand, do it all 
the time. Often, a good cleaning 
with a pencil eraser will do won- 
ders — and that brings us to the 
ultimate crunch machine: 

The ubiquitous HT 

Although lots of different kinds 
of rigs can crunch, the ones I hear 
most often, and the ones I' ve most 
commonly had to fix, are 
handhelds. Heck, Fve seen brand- 
new NTs that were crunchy right 
out of the box. Why are HTs so 
prone to this problem? There are 
several reasons. First, the RF out- 
put is usually via rubber duck an- 
tenna, which puts a great deal of 
RF right back into the walkie. 
That can lead to crunchies for rea- 
sons Til shortly explain. Second, 
HTs are very small constructs, 
with sensitive stages quite close 
to each other, shielded only by 
small amounts of thin mctaL Fi- 
nally, handhelds take a lot of 
physical abuse, due to their being 
carried around all the time. 



Shield me 

When there's lots of RF pound- 
inn on the shields of sensitive cir~ 
cuits, as there often is in a 
rubber-duck HT, those shields had 
better be nice and tight! Even a 
cold solder joint can exhibit 
enough rectifying ability to cause 
RF feedback. Heck, even the 
unsoldered edges of small shield 
cans are capable of spreading the 
RF around unevenly enough that 
there's some potential between 
various parts of the shield. That 
makes the shield into a radiator, 
and it radiates RF right into the 
circuits it's supposed to shield- 
Now, if the exact properties of 
that shield vary as you squeeze or 
move the rig, what do you get? 
Yup, the crunchies! 

The average modern walkie is 
constructed in two halves, usually 
with a ribbon connector between 
them, That's in sharp contrast to 
the old style of construction, 
which had one big board in the 
middle of the frame, and perhaps 
a small microprocessor board be- 
hind the keypad. The old way was 
better in one respect: It rarely led 
to the crunchies, because the 
grounds were all tied to the same 
frame. The newer, split style 
means that, right off, there are two 
grounds, one on each side, Re- 
member, at VHF and UHF, it only 
takes a fraction of an inch for a 
ground plane io become an induc- 
tor, and that spells trouble with a 
capital "C." Most HTs have a 
metal tongue that extends from 
one side to the other and is in- 
tended to connect the two 
grounds. Does it work? Well, kind 
of, When the rig is new and clean, 
it works pretty well, but as the 
handheld ages and a little grime 
gets in there, and the tongue's 
spring tension relaxes, the integ- 
rity of that all-important eonnee- 
tion gets questionable. You 
squeeze the rig, causing the 
tongue to rub slightly against its 
contact on the opposite side of the 
radio, and it makes that charac- 
teristic sound. The rig goes 
"crunch." 

Mostly on TX 

Why does this problem affect 
transmitting so much more than 
receiving? On receive, there's no 



54 73 Amateur Radio Today * February 1997 



big source of RF against which 
the shields have to protect. Sure* 
the various internal oscillators 
make some noise, but not at the 
level of watts of power! Shield- 
ing and grounding problems that 
aren't even noticeable on re- 
ceive can be troublesome on 
transmit. 1 remember one stub- 
bom case of the crunchies in a 
brand-new HT that turned out to 
be a cold solder joint on one of 
the four corners of the shield 
over the VFO circuit. The rig 
worked fine on receive but was 
intolerably crunchy on transmit. 
As it turns out, VFO and PLL 
circuitry is particularly sensitive 
to shielding problems. Heck, 
this radio had three of (he 
shield's four corners soldered 
just fine, and it still didn't work 
right! If you have a crunchy rig 
and the obvious solutions arcn*t 
working, check those shields on 
the circuit board, You can usu- 
ally spot the ones over sensitive 
circuitry because there'll be a 
hole for adjusting a coil or trim 
cap. 

I had another crunchy handheld 
I was sure had this problem. 1 sol- 
dered everything 1 could find, and 
it still crunched, 1 even soldered 
parts of the frame together, be- 
cause they were held only by tiny 
rivets, and I thought perhaps that 
was the problem. No dice. No 
matter where I pressed, the rig 
crunched. It finally turned out to 
be a dirty BNC antenna connec- 
tor! [cleaned the hole on top with 
a tiny rolled-up piece of paper 
soaked in contact cleaner, and the 
problem went away, From now 
on, PU always check those BNCs. 
After all, the contact area is pretty 
small, and it's exposed to lots of 
environmental stuff like dirt, 
smoke and moisture, so it makes 
sense to expect trouble there. 

By the way, HF rigs can be 
crunchy, too, often for the same 
reasons as VHF/UHF radios. 
Some cases of HF crunching, 
though, are caused by simple RF 
feedback into the microphone 
amplifier circuit, so always check 
for that by transmitting into a 
dummy load before assuming the 
radio has a real problem. 

Well, I think we've crunched 
enough for one month. Nexttime, 
we'll look into something else. Until 
then,73deK£lUM. 



Neuer sry die 

Continued from page 43 

and not one like 99.99% of the 
magazines you read, but like 
mine. What would you write 
about? Try sitting down at your 
word processor and let's see 
what you can come up with. 

Have you had an exciting ad- 
venture in amateur radio? Have 
you read a book that you think 
everyone really should know 
about? If you haven't had any 
exciting amateur radio adven- 
tures, why the hell not? What's 
wrong with you? The doors to 
adventure are right there in front 
of you at every turn. Are you 
blind? And if you haven't read a 
truly fantastic book recently, 
why not? 

Have you done anything, 
learned anything, built anything, 
which might be of interest to the 
73 readers? If so, start writing. If 
not, get a life. It doesn't have to 
cost a lot to get on packet or our ham 
satellites. Heck, a DXpcdition to Sl_ 
Pierre or Anguilla doesn't cost 
much, and will give you things to 
write (and even talk) about for 
years. 

Or maybe you're a CW fa- 
natic and can tell us how you 
went about learning to copy the 
code at 50 wpm? Or faster? If 
you wanted to, I'll bet you could 
learn to copy 50 wpm in two or 
three weeks and have the time of 
your life. But then you might 
want to get Congress to pass a 
law making everyone else learn 
to copy 50 wpm. Or become an 
ARRL Director. Or both. 

You're an editor. You have a 
deadline coming up in a couple 
of days. What are you going to 
write about? Now get busy. If 
you can get me excited enough, 
I'll publish it. Oh yes, don't for- 
get to send both hard copy and a 
disk. And please don't forget to 
use your spell checker. 

Til tell you what. If I find I'm 
getting more good stuff than I 
can fit into 73, I'll reprint your 
editorials and send copies to the 
editors of the several dozen ham 
club newsletters I'm getting. 
Many of 'em are in pathetic need 
of interesting material. 

Once you get the hang of writ- 
ing you'll be surprised at how 
easily the ideas come. Tve never 
had a time when I sat down to 
my typewriter or word processor 
and was stumped for something 
to write about. No dry spells. 
Worse, I've gotten way ahead. A 
few months ago I published a 

Continued on page 69 



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Homing in 



Number 56 on your Feedback card 



Joe Moell RE. K0OV 
PO Box 2508 
FullertonCA 92633 



Build a multiple 
polarization quad 

Cubical quads are the most 
popular antennas for VHF and 
UHF radio direction finding 
(RDF) in many places around the 
country, including Southern Cali- 
fornia. One reason why you see 
so many quads on vehicles at our 
hidden transmitter hunts (T-hunts) 
is that quads can easily match the 
polarization of the hidden signal. 
This can make the difference be- 
tween success and failure in some 
cases. 

Let's say that the signal you're 
tracking has horizontal polariza- 
tion, but you are using a verti- 
cally-polarized RDF system 1 . 
This cross-polarized condition 
means that the direct incoming 
signal is between 14 and 25 dB 
weaker in your receiver, reducing 
your effective RDF range. Worse 
yet, any signals from the hider 
that propagate to you by reflec- 
tion from nearby buildings, inter- 
mediate hills, and distant 
mountains undergo a polarization 
shift. That makes them appear 
stronger, relative to the direct sig- 
nal, than they would if your an- 
tenna had horizontal polarization. 
As a result, you might end up 
chasing reflected signals through- 
out the entire transmitter hunt, 
never getting accurate bearings on 
the direct signal. 



Radio Direction Finding 



With a simple slip joint at the 
boom-to- mast junction, a 2 meter 
quad is easily changed from hori- 
zontal to vertical polarization or 
to any other linear polarization 
angle. By adjusting your quads 
polarization to maximize signal 
strength at the start of each T- 
hunu you can avoid the problems 
of hunting cross-polarized 
signals. 

The slip joint method has a few 
drawbacks. Sometimes it's not 
easy to tell for sure what polar- 
ization the hider is using, so you 
must check again occasionally as 
you progress toward the T. That's 



with separate feedlines and a 
switchhox to select six polariza- 
tion modes. Many T-hunters. in- 
cluding your columnist, prefer 
quads to yagis because they are 
more compact. A typical mobile- 
mounted quad provides a better 
RDF pattern than a yagi of the 
same size. Hence. 1 have consid- 
ered designing and building a 
multiple-polarization RDF quad 
for a long time. A recent inquiry 
bv KD6IFZ on the Internet T- 
hunting mailing list motivated me 
to move the project onto the front 
burner, 

One quad, two feedlines 

While separate driven elements 
for horizontal and vertical polar- 
ization on one quad could 
probably be made to work, a more 



"By adjusting your quad's polarization 
to maximize signal strength at the start 

of each T~hunt, you can avoid the 
problems of hunting cross-polarized 

signals. " 



not fun if you have to stop and 
get out in the rain. Sometimes 
there are several transmitters to be 
found with different apparent po- 
larizations, requiring frequent 
changes. Wouldn't it be better to 
be able to make the selection 
quickly from inside your vehicle? 
Crossed yagis have been suc- 
cessfully used by T- hunters for 
polarization agility. Back in April 
1 989, "Homing In" described the 
setup of Vince Stagnaro 
WA6DLQ, who put the elements 
of two KLM yagis on one boom 




Fig. I. At (a), the driven element of a horizontally-polarized quad. 
The feedlme connects to point A. Breaking the loop at point D as in 
(b) does not affect horizontally-polarized operation. Attaching 
feedlines at A and D as in (c) allows extraction of both horizontally - 
and vertically-polarized signals, if the outs ides of the coaxes are 
decoupled. 

56 7$ Amateur Radio Today • February 1997 



elegant solution would take ad- 
vantage of the cubical quad*s in- 
herent symmetry, which makes all 
elements able to support both po- 
larization modes simultaneously. 

Let's go back to basics for a 
moment. AC currents at VHF fre- 
quencies in antennas behave dif- 
ferently from AC currents at 60 
Hz in your bouse wiring. The 
quantity of electrons passing per 
second along the power cord of 
your toaster is the same at the plug 
end, the toaster end. and every- 
where in between. But if you 
could measure the RF current at 
several points along the driven 
element (DE) of a quad antenna, 
you would find that it differs. This 
properly makes the DE radiate 
transmitted signals and pick up re- 
ceived signals. 

Fig* 1(a) shows a typical quad 
driven element loop. Circumfer- 
ence is one wavelength, about 80 
inches at 2 meters. The feedlme 
is connected to point A, which 
gives a horizontally-polarized 
transmitted signal. Received sig- 
nals of horizontal polarization in- 
duce currents in the loop that go 
down the feedline to the receiver. 




Photo A. One 

of the 50- head 
hahms without the 
heat-shrink 



Vertically- 
pol arized 
signals in- 
duce cur- 
rents within 
the loop 
also, but 
magnitude 
and phases 
are such that 
they cancel 
out at point 
A. 

RF cur- 
rent from 
the transmit- 
ter is highest 
at point A, 
There is an- 
other trans- 
milting 
current 
maximum 
at point C. 
At points B 
and D, cur- 
rent is at a 
minimum. Theoretically in a per- 
fect quad, loop current would be 
zero at these points. In a practical 
beam, it is less than 1 percent of 
the maximum. 

If there is indeed no current at 
point D, why can't we just break 
the loop there, as in Fig. 1(b)? 
You can! If you have antenna 
analysis software such as 
ELNEC 2 , try this as an "exercise 
for the reader.' 1 Insert a very high 
value resistive load at point D 
in the DE of vour favorite dia- 
mond quad model for any band. 
If the quad is symmetrical, then 
the resonan frequency, pattern 
and feed point impedance will 
show very li t tie change. 

With ihe added break, we 
have the driven element of Fig* 
1(b), Feeding it at point A gives 
horizontal polarization, while 
feeding it at D gives vertical po- 
lar izal ion. Bolh modes can be 
handled by the quad simulta- 
neously. So why not just hook a 
feedline to each point and switch 
from one to another at the 
receiver, as in Fig. 1(c)? 

Whoa! Breaking the loop and 
adding aSO-ohm load at a current 
minimum will not affect it, but 
adding an unbalanced feedline 
certainly will. The braid of the 
coax becomes part of the antenna. 
As another ELNEC exercise, 
hang a long wire (representing the 




Photo B, Close-up of a feed poms 
Mock. The first bead fits over the 
point where coax shield and cen- 
ter conductor are separated. 

coax shield) at a current null point 
in your favorite quad DE and 
watch the pattern change for the 
worse. 

Fortunately, current flow on the 
outside of the coax can he choked 
off to restore the current mini- 
mum. A bahinced-to-unbalanced 
transformer (balun) will Jo it. RF 
current will he confined lo the 
coax inner conductor and the in- 
side of the shield, and will remain 
near zero for cross-polarized sig- 
nals. For the unused polarization 
mode, it is almost as if the coax 
isn't thereat all! 

VK5RN has documented a 
circularly-polarized quad for 
OSCAR satellite work that has 
two feedlines with sleeve 
haluns-. These devices, some- 
times called bazookas, are 
made from thin-wall metal 
tubing of carefully selected 
diameters, I did not want to 
use a pair of bazookas on my 
T-hunt mohtlc quad because 
they are heavy and would add 
lots of asymmetrical windload 
at freeway speeds, Instead. 1 
tried a choke of ferrite beads. 
Measurements by W2DU 4 
show that 25 beads of #43 fer- 
rite material over a coax line 
provide 850 ohms impedance 
to currents on the outside of 
the shield at 2 meters. 



it work? 



1 but It a modified Cubex 
Yellowjackct* four-element 2 
meter quad by installing two 
feedline termination blocks in- 
stead of one. Part number FB- 



43-2401 beads* have an inner di- 
ameter of 3/l6'\ so they fit 
nicely over the RG-58/U 
feedlines once the outer jacket 
is removed. The iwo feedlines 
go down the 3/4" Schedule 40 
PVC pipe mast to a two- position 
coax switch in the van t then to 
the receiver. Coaxes arc exactly 
the same lengths to make it 
easier to achieve circular polar- 
ization, as will be shown later. 
At a local hilltop, I compared 
the new dual-polarization quad 
to an unmodified Cube* 
Yellow-jacket using a calibrated 
attenuator plus local and distant 
repeater signals. The results de- 
lighted me. The directional pat- 
tern of the dual-quad was just as 
good as that of the reference 
quad. Cross-polarized signals 
were attenuated 14 dB by the 
dual-quad, which represents 
about 3/4 scale on my receiver's 
S-meten 

Forward gain of the dual -quad 
was about a half dB less than the 
reference, a negligible differ- 
ence. Making the comparison 
was difficult because when test- 
ing the stock quad, the S -meter 
would vary plus or minus 20% 
as the feedline was moved 
around inside the van, due to 
feedline signal pickup. On the 
other hand, output of the dual- 
quad was rock solid with 
feedline movement, thanks to 
decoupling by the ferrile haluns. 
About this time, a Saturday 
night mobile T-hunt was getting 
underway. I decided to give the 
quad a real workout. KD6LOR 
and KK6ME had put out three 
hidden T's, transmitting inter- 
mittently on 146.565 MHz. 
Only one was copyable when I 
left the hilltop. By switching 
between feedlines, it was easy 
to tell that this signal had hori- 
zontal polarization. After 1 had 
gone a few miles, I began to 
detect weak signals after each 
transmission from the strong T. 
I loggled the coax switch a few 
times and determined that the 
weak signals were stronger in 
the vertical mode. 

I found the strong signal first. 
It was in KD6LOR's truck in a 
parking lot overlooking Mission 
Viej< *. Sure cm mgh, its transmitting 
antenna was a horizontally-po- 
larized quad. J then look on the 



other two T*s, which clearly had 
vertical polarization. There was 
now a bit of overlap in the trans- 
missions and it was nice to be 
able to switch polarization to 
minimize the signal from the 
horizontal T while hunting the 
others. 

Before long, 1 had found both 
of the weaker Ts. Each had a 
quarter-wavelength vertical 
whip antenna mounted on a sur- 
plus ammunition can. One was 
chained to the base of a high 
voltage power line transmission 
tower, while the other was in a 
park on a steep hillside over- 
looking Lake Forest. This hunt 
was enough to convince me that 
a polarization-agile quad would 
be my new 'weapon of choice" 
for many future hunts. 

Although gain and pattern 
of the test quad proved to be 
excellent, SWR was over 
2,5:1. Upon further teshng, 1 
found that the DE was reso- 
nant at about 141.5 MHz. Ap- 
parently the pigtails between 
the ends of the bead haluns 
and the feedline blocks add to 
the DE's resonant length. I 
shortened the DE wires, which 
improved SWR but caused the 
pattern's back lobe to worsen. 
After some experimentation, I 
found that moving the reflec- 
tor four inches closer to the 
DE made the SWR even bet- 
ter and minimized the back 
lobe. 

SWR is now 1.6:1 for both 
polarizations. This is fine for 



receiving, because the feedline 
is decoupled well. Your receiver 
probably does not have exactly 
50 ohms input impedance any- 
way. I also tried 50 beads per 
balun instead pf 25 (Photo A), 
This increased cross-polarized 
signal rejection from 14 to 17 
dB, 

You can make one 

Your favorite 2 meter cor- 
ner-fed no-gamma diamond 
quad design should be suitable 
for use with this dual -polariza- 
tion feed technique. Baiuns of 
25 beads each are adequate for 
RDF and inexpensive, 7 You 
will need to strip the jacket 
from RG-58/U coax for the 
beads to fit. Do noi strip or 
comb the shield braid under 
the beads. If your coax diam- 
eter is so small that the beads 
will go over the jacket, it is not 
standard RG-58/U and not 
recommended for VHP. 

Cover each balun with heat- 
shrink tubing and add ;i dot lop 
of hoi glue or other sealant at 
the ends before shrinking to 
keep water out. Keep the 
shield and center conductor 
leads from balun to feed block 
short. Remember that they add 
to [he DE resonant length. 
These pigtails are just 3/4" 
each on my quad (Photo B), 
compared to 1*1/2" in the 
Cubex instructions. 

As a check of your dual- 
feed quad's construction, try 




Photo C. The dual -quad is mounted and ready for a hunt. Note 3 that 
the feedline passes over the fop of the boom, but does not wrap 
around as it does in stock Yeltowjacket quads. 

73 Amateur Radio Today ■ February 1997 57 



transmitting on 2 meters into one 
teed line while terminating the 
other with a wattmeter and a good 
VHP dummy load. Very little RF 
should leak from coax to coax. In 
my case, transmitting 22 watts 
into the horizontal coax gave only 
6 milliwatts out of the vertical 
coax* and vice versa (35 dB iso- 
lation l 

Wire lengths of the DE on ray 
modified Yeltowjacket are 18-3/ 
4" for the wire between the two 
feed blocks (measured screw-to- 
scrcw), and 59-3/8" for the wire 
that forms the other three sides of 
the loop. Lengths of the other 
Cubex element wires are tin- 
changed, Cubex instructions call 
for six turns of fccdline around 
the Yellowjacket boom, hut these 
added turns are unnecessary and 
undesirable when the ferrite 
baluns are in place (Photo C). 
Cubex suggests using RGSX low- 
loss fecdline. but the difference in 
loss for short mobile T-hunting 
feedlines is neelisibie, 

Hiders occasionally transmit 
unusual polarizations. For in- 
stance, an ammunition-can T 
propped up in a iree may put out 
a signal polarized at a 45 -degree 
angle between horizontal and ver- 
tical. There have even been some 
circularly polarized T's to find on 
our Saturday night hunts. 

By combining signals from the 
horizontal and vertical feedlines 
of the dual-quad with proper 
phase relationship, you can 
achieve 45-degree and circular 
polarizations. "Homing In" tor 
April 1989 has plans for 
WA6DLQ*s six-position polariza- 
tion switchbox. Though intended 
for use with his dual-feed vagi, it 
will also work with the dual-quad 
A similar switchbox is in the Ra- 
dio Society of Great Britain's 



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VHF/UHF Manual, Feedlines 
from switchbox to each feed point 
must be exactly equal lengths 
when using the switchbox. 

If T-hunting in your area re- 
quires you to make frequent po- 
larization decisions, consider 
adding a dual -polarization quad to 
your bag of tricks. Ed Buchanan 
of Cubex has agreed to sell a dual- 
feed version of the Yellowjacket 
quad lo "Homing In" readers. It 
includes two feed point termina- 
tion blocks and associated hard- 
ware. Contact Cubex directly and 
ask for the T-hunt Special. Please 
understand that I have no business 
association with Cubex, so do not 
send inquiries about this offer to 
me. 

Whether you make your own 
dual-polarization RDF quad or try 
the modified Cubex Yellowjacket, 
let me know how it works 
for you. Send E-mail to 
Homingin@aol.com, or write to 
me at the address at the beginning 
of this article. Don't forget to 
check out the Homing In Web 
site: http:V/members.aoLcom/ 
homingin/ is the URL. 

References: 

L Dopplers and time-differ- 
ence -of -arrival RDF sets use ver- 
tically polarized dipoles or 
ground plane antennas. 

2. Available from Roy 
Lewallen W7EL, P.O. Box 6658, 
Beaverton, OR 97007. 

3. Robertson,* The Quadraquad 
— Circular Polarization the 
Easy Way," QST, April 1984, page 
16. 

4, Maxwell, 4 *Some Aspects of 
the Balun Problem," QST. March 
1983, page 38. Ferrite baluns are 
also briefly described in recent 

editions of The ,ARRL Handbook, 

5, Cubex Quad Company, 2761 
Saturn Street, Unit C. Brea, CA 
92821; (714) 577-9009. 

6. Available from Amidon As- 
sociates, P.O. Box 956, Torrance, 
CA W508; (310) 763-5770. 

7. Prices for FB-43-2401 beads 
from Amidon are $4.50 per dozen 
or $ 16 per hundred, plus shippinj 
handling. 



Number 58 on your Feedback card 



Rboue & Beyond 



VHF and Above Operation 



C, L Houghton WB6IGP 
San Diego Microwave Group 
6345 Badger Lake Ave 
San Diego CA 92119 
clhough@aol.com 



Microwave Stripline 
Retuning Procedures 

This month I would have liked 
to cover the synthesizer that I 
used for the 1 296 MHz transverter 
presented last month. However, I 
haven't completed the conversion 
documentation in sufficient de- 
tail. I have made the unit function 
as described. Still, notes and other 
details must be reconfirmed for 
accuracy — I will get the details to 
you as soon as possible. 

Instead, this month I will con- 
tinue trying to provide ideas on 
how to convert surplus micro- 
wave material for use on the ama- 
teur bands. This has been partially 
covered, but here are the full- 
blown details covering tuning 
procedures, and specifically the 
methods that Kerry N6IZW and I 
use in converting microstripline 
circuitry. These procedures were 
developed by Kerry and arc pre- 
sented in a general format, suit- 
able for all microwave/UHF 
amateur bands of interest. Here 
are Kerry N6IZW*s modification 
details for retuning surplus micro- 
wave microstrip circuits for the 
amateur bands: 

In recent years, considerable 
quantities of surplus microwave 
equipment have become available 
to the amateur community. The 
reasons for adapting surplus 
equipment rather than building 
from scratch often include cost, 
time and performance. The cost 
for a typical piece of microwave 
surplus purchased by an astute 
amateur will be far less than the 
cost of a few new components. 
Often many hours that would oth- 
erwise spent in locating compo- 
nents, fabricating boards, and 
building enclosures are saved. 

The performance obtainable is 
usually quite good due to the 
commercial processes used 
to fabricate the units in quantity. 
Most surplus microwave 



equipment is tuned for commer- 
cial or military frequencies, mak- 
ing it unusable on amateur 
frequencies without modification. 
This is what causes (he same 
piece of equipment to be so much 
junk for one person, but a trea- 
sure for someone equipped for 
retuning. 

High technology: good 
news and bad news 

Microwave circuit fabrication 
techniques have progressed from 
waveguide to microstrip printed 
circuit boards to ceramic substrate 
hybrids to large-scale monolithic 
integrated circuits. Waveguide- 
type equipment still finds favor 
among those beginning on the 
amateur bands at 5.7 GHz and 
above, but microstrip circuits are 
prevalent among those building 
medium- lo high-performance 
amateur equipment through 24 
GHz. The good news is that the 
microstrip surplus is lypieally 
available because the industry is 
moving into higher and higher in- 
tegration technologies such as the 
hybrid or MM1C. 

The bad news is that the newer 
technology equipment often con- 
tains integrated components 
which are internally matched or 
tuned for a specific frequency and 
are not practical for most ama- 
teurs to modify. An example of a 
nonmodifiablc piece of surplus is 
the typical VSAT terminal now 
becoming available, These units 
contain >1 watt transmitters at 14 
GHz and low-noise receivers 
around 1 2 GHz T but are so highly 
integrated that very few of the mi- 
crowave components arc usable 
for amateur purposes. 

The conversion of microwave 
surplus equipment m;iy eventu- 
ally dwindle as the modifiable 
technologies disappear, but this 
should not be a problem for some 
years to come. Another good side 
of the newer technologies is that 
they provide high performance 
with low cost and case of appli- 
cation for those assembling their 
own microwave circuit boards 



58 73 Amateur Radio Today * February 1997 



using new components. Below 
are some examples of success- 
fully modified surplus equipment. 

C-band TVRO LNAs 

These low- noise amplifiers are 
available in the $5 range at local 
flea markets. In their original con- 
dition, they provide about 50 dB 
gain with a 1 dB noise figure over 
the 3.7 to 4.2 GHz range. They 
require aboui + 1 5 lo +24 lo oper- 
aie with power being supplied lo 
the output connector. When the 
internal filters are removed the 
amplifier is usable over the .8 lo 
4.2 GHz range, with the noise fig- 
ure increasing to about 3 dB at the 



may change the output by less 
than 1 dB. The signal level needs 
to be large enough at the begin- 
ning lo have measurable output 
appear but should be reduced to 
keep any stages from possibly 
saturating. For small signal de- 
vices the input should not exceed 
about +5 dBm to prevent device 
damage. 

Attenuators 

Attenuators (3 dB minimum) 
should be applied directly to the 
input and output of the circuit to 
be tuned, for two reasons: To re- 
duce any possible test setup mis- 
match that might otherwise be 



"An astute amateur can buy a piece of 

microwave surplus for much iess than 

the cost of a few new key components. 



compensated for in the tuning 
process, and to protect the power 
measuring equipment and the 
equipment being tuned. This is a 
particularly important point when 
working with power amplifiers 
which may accidentally oscillate 
during the tuning procedure. 

Power monitors 

Almost any type of power 
monitor can be used as long as it 
lias sufficient resolution and sta- 
bility to identify changes of .5 dB 
or less. 1 started with a spectrum 
analyzer but found a power meter 
to be much more satisfactory for 
detailing small changes. 

Power supplies 

Power supplies should be well 
regulated and have current limit- 
ing which is adjustable to just 
above the nominal operating cur- 
rent. The bipolar devices typically 
use a single power supply while 
[he GaAs devices typically re- 
quire a negative gate bias. The 
gale bias should normally be ap- 
plied prior to applying the drain 
voltage to prevent possible device 
damage caused by the transistor 
attempting to turn on hard. 

My experience has been thai 
the properly adjusted current-lim- 
ited supply will prevent device 
damage should the gate bias be 
accidentally removed during the 



low end. I have used one of these 
units as the 2.4 GHz LNA for an 
OSCAR- 13 receiver. 

Ku-band power amplifiers 

Several types of 14-14 + 5 GHz 
power amplifiers with 25 dB or 
more gain and ,5 to 2 watts out- 
put are available for about $35, 
These units are readily reUinahte 
for use on the 10 Gil/ amateur 
band, with somewhat increased 
output over that available at 14 
GHz. 

Ku-band LNA 

Several types of Ku-band 
TVRO and VSAT LNAs are 
available in the $20 range. These 
can typically be retuned for use 
on the 1 GHz amateur band, pro- 
viding 20 dB gain and a I to 3 dB 
noise figure. 

Tools and test equipment: 
signal sources 

Almost any available source 

that can be set to the frequency 
range of interest can be used. Us- 
able sources include commercial 
signal generators as well as Gunn. 
transistor, FEZ and Y1G oscilla- 
tors. The frequency stability of 
most sources is more than ad- 
equate for tuning microstrip cir- 
cuits. Short-ierm amplitude 
stability is needed; often a single 
matching element adjustment 




m 



Fig. 1. Typical microstrip circuit components, showing layout of 
microwave amplifier filters and associated stripline components: 

1. RF input I output connectors 

2. Main 5012 microstrip transmission line 

3. DC blocking/interstage coupling capacitors 

-f + High impedance bias lines > 1 00X2, usually 1/4 wavelength (as 
long as these are narrow lines, no modification needetl 

5. 1/4 wave pads to provide RF ground to bias lines (open one end), 
normally no modification needed 

6. Matching stubs may be symmetrical or asymmetrical {may need to 
be removed for best results) 

7. Bipolar <>r FIT device: F FT gate values typically -J to -15V; FET 
drain values typically +2 to +9V 

8. Emitter or source ground pads (direct connection to ground plane 
is critical) 

9. Interstage fitter/DC block; typically, cut with craft knife and 
insert capacitor (difficult to re tune} 

10. 1/4 wave bandpass fitter (one end grounded), typically discon- 
nected at main transmission line; possibly re tunable if length/ ground 
point can he modified 

1 1 . Bandpass Jitter, modifiable with some success by symmetrically extending 
all elements of filter. 



tuning process. Always remove 
power when making connections 
and soldering tuning stubs. 
Make sure the amplifier output is 
l c r m i nat ed be fore applying 
power. The power supply ground 
output should be connected to 
earth ground. 

Soldering on 

A soldering iron with a very 
small grounded tip is essential. 
The grounded tip is absolutely 
necessary to prevent 60 Hz power 
line or static potential from dam- 
aging GaAsFET devices. Small 
signal GaAsFHTs are often dam- 
aged if the gale voltage exceeds 
3 lo 5 vults. The drain voltage 
limit is typically 5 lo 8 volts. The 
limit for power devices is usualh 
a feu volts higher. 

Microstrip tuning 

techniques 

Here is the bask approach I 

73 Amateur 



have used to retune many 
surplus amplifiers: 

Everything must be grounded 
to power (earth) ground includ- 
ing the soldering iron tip. The 
typical FETs in microwave ampli- 
fiers will self-destruct with more 
than 5-10 volts on the gate. 

Apply only as much input RF 
power as required to get usable 
output measurement. This re- 
duces the chance of damage to 
higher power devices prior to get- 
ting the ouEput matched. Also, it 
prevents saturation of a siage 
which then appears noi to respond 
to tuning. Applying more than 
about +10 dBm directly lo small 
FETs may cause damage. 

Use current-limited power sup- 
plies set to limit slightly above the 
normal expected operating cur- 
rent. This will in most cases pre- 
vent blowing up the FETs if the 
negative gate bias is missing or 
something is accidentally shorted 
with the tuning wand. With this 
approach^ sequenced turn on of 
Radio Today * February 1997 59 



Ihe power supplies is not usually 
important. 

Place attenuators directly at the 
input and output of the amplifier. 
This removes the effect of poor 
cable, source and power detector 
matching. Always remove power 
when making connections and 
soldering tuning stubs. Make sure 
the amplifier output is terminated 
before applying power. 



ohm line. Be careful not to cut the 
thin brass lines. If you are unsure 
of possible damage to the bias 
lines, carefully check continuity 
or use a magnifier to do visual in- 
spection before applying power. 
In some cases it pays to go 
through the agony of removing 
the stub completely as the correct 
new stub placement may overlap 
and cause problems. 



"Several types of 14-14.5 GHz power 

amplifiers are readily retunable for use 

on the 10 GHz amateur band," 



Tuning procedure 

Prepare the tuning wand and 
tuning stub material. Cut about 1" 
or T strips .080" wide (not criti- 
cal) of about the same width as 
the main 50 ohm microstrip lines 
in the amplifier from thin copper 
or brass stock (.003" to .010"). Tin 
both sides of the strips and flick 
off excess solder. Make several 
tuning wands by cutting one end 
of a wooden toothpick square at 
the largest diameter. Using 
SuperGIue™, attach a square 
(,080" x .080") of the prepared 
tinned copper or brass to the 
curved end of the toothpick. Wipe 
off excess glue from the exposed 
side of the square and let dry. 

Remove existing tuning stubs. 
Using an X-Acto™ knife, make a 
deep enough cut to disconnect 
tuning stubs from the main 50 



Connect the amplifier to the 
signal source, attenuators, power 
detector and power supplies, Turn 
on the power and adjust input at- 
tenuation for as low an input as 
can be readily detected on the out- 
put. Start at the output and slide 
the tuning w r and along (in contact 
with) the main 50 ohm line, 
watching for an increase in out- 
put. Note the maximum output 
reading obtained with the wand. 
Remove power and solder a 
square of the prepared material in 
the same position as noted by the 
wand. 

Do not add solder. The tinning 
is normally sufficient to allow the 
new tuning stub to be held in 
place with the pointed end of a 
toothpick and then just touched 
with the soldering iron to reflow 
the solder. Turn on the power and 



verify that the output is as high 
or higher than obtained with the 
wand. Move the tuning stub if 
required to obtain results equal to 
or better than those of the wand. 

Slide the wand over the previ- 
ously attached new stub and if 
improvement can be made, attach 
another square. Continue this for 
the entire length of the main 50 
ohm line until no further improve- 
ment is found. Increase the input 
power if working with a power 
amplifier and re tune the output 
stage for maximum power. Be 
careful here not to mismatch the 
output so badly with the wand as 
to damage the FET. 

The process can be very slow, 
with some stubs only gaining a frac- 
tion of a dB. In most cases it will 
take all of those small increases to 
get good results so don't expect to 
see major improvement with a 
few stubs. It may take four stubs 
per stage sometimes to get the 
maximum output. 

Additional notes 

Direct grounding of a micro- 
wave power device emitter/ 
source is essential for proper op- 
eration. Any form of insulating 
grease can prevent full gain/ 
power output from being 
obtained. 

When mounting boards into 
enclosures, take care to ensure 
that the entire perimeter of 
the board is connected to the 
enclosure to prevent oscillatioa 



Power (Earth) 
Ground 



Power 
Supply 



-B 




+V 



Power (Eartt 
Ground 


o 


Soldering 

Iron With 

Grounded 

Tip 







Signal 
Source 




Atten. 
at Input 

of Amp 




V 



Amplifier 
Being 
Tuned 




Atten. 

at 
Output 

of Amp 




Power 
Indicator 



Fig. 2. Equipment configuration for retiming microstrip amplifiers, 
60 73 Amateur Radio Today ■ February 1997 



Letters 

Continued from page 7 

truly are the unsung heroes of ama- 
teur radio — I thank you all, and 
please do keep up the great work! 
There are people out there who 
really do appreciate it. 
Aw, shucks.., Wayne. 

Roger Wendell WB0JNR. 

Wayne, in l 'Never Say Die" you 
asked if we'd like to hear you talk 
about something besides ham radio. 
You bet! How about the beauty of 
3 5 billion years of organic evolu- 
tion and what hams can do to save 
it? We don't need any more money 
schemes, dirty religions, or mind- 
less hobbies — we need more of 
nature — the real world, 

Roger, I've flown over the Pacific 
Northwest, soVve seen the ugliness 
ofclearcutting our forests. Fve seen 
the horrendous scars of strip min- 
ing. Vm also seeing the pollution 
of the radio frequencies, with 
around 30,000 rock music radio 
stations crowding my AM and FM 
dial, and 200 or so TV channels of 
mind-rotting crud, Our school sys- 
tem is crumbling. Our health care 
system is just as bad as our school 
system. Crime, drugs, welfare, and 
so on. Yes t we *ve made a real mess 
of our states, country and planet 
and we're trying to figure out how 
to go out and spread it to other 
planets. So what do we do, knuckle 
under and try to cut as big a piece 
of the pie as we can for ourselves, 
and to hell with ihe mess we make 
doing it? Or do we fight? But how 
can you fight City Hall? I've al- 
ready proposed a way we can se- 
cretly infiltrate the "system" and 
start changing it, working from the 
inside, Roger, we hams are 700,000 
strong, but only if we're working 
together. As individuals we re of no 
significance. Yes, as small a group 
as we are— we have the potential 
to change our cities r our states, our 
country, and then the world. Our 
foes are entrenched interests, apa- 
thy, and indifference. Our strength 
is a never-say-die attitude . Motiva- 
tion . Determination . Perseverance . 
Roger, 700,000 people can be an 
army... Wayne. 

Cliff Gieseke W4ZFL, UFOs 
are a topic Fve been fascinated with 
since the early 7 50s» when 1 was First 

Continued on page 62 



QRP 



Number 61 an your Feedback card 



Michael Bryce WB8VGE 
RO. Box 508 
Massillon OH 44648 

This month, I have some more 
odds and ends for you. These cir- 
cuits and tidbits may help you 
enhance the performance of your 
QRP equipment. 

A&A Engineering RIT 
modifications 

The first project comes from 
John Best, Sr. WA1YIH. John 
took the RIT circuit for the MFJ 
QRP monobanders and modified 
it to work with the Gary Breed 
K9AY/A&A Engineering 30 
meter rig. The original circuit ap- 
peared in 73 's "QRP" column for 
November *95. Here is John's 
modification; 

"I modified the RIT circuit for 
the MFJ rigs to work with my 
A&A Engineering QRP trans- 
ceiver. I used a Radio Shack 
IC board, 276- 1 59, and ugly 
construction. 

"To modify the rig, you have 
to remove the fine-tuning control. 
The fine-tuning control connects 
to the main tuning circuits. The 
wire that goes from the main tun- 
ing to the fine-tuning is removed 
and hooked to R2 (the 470 ohm 
resistor). The wiper of the fine- 
tuning is grounded. One side of 
the fine-tuning is connected to 
pin 2 of the 4066. The rest of the 
circuit is self-explanatory," 

John reports that he gets ap- 
proximately 800 Hz offset on ei- 
ther side of the R [T control center 
position. John's RIT indicator is 
pretty simple. He used a dual-col- 
ored LED, Radio Shack™ #276- 
025, and a DPDT switch. 

John says, ''I use the green as a 
rig power indicator as well as RIT 
off, and the red for RIT on/" 

With the fine-tune control out 
of the circuit, I would suggest you 
replace the original single- turn 
tuning control with a multi-turn 
pot. Fve seen these units listed as 
surplus for under 10 bucks. Also, 
if you favor one segment of the 
band over another, 1 would 
change the voltage divider used 
to drive the VXO, Expanding the 
range within a segment will give 



Low Power Operation 

you super-smooth tuning. On the 
downside, it would be real slow 
to go from one end of the desired 
segment to the other. 

Wimpy 386 audio 

If you've ever built a QRP rig, 
it's a good bet you've used the 
LM386 audio amplifier. It's al- 
most a standard part — every QRP 
builder should have one in his or 
her junk box. 

However pleased you may be 
with your home-brewed or com- 
mercial rig using an LM386 for the 
audio output stage, you can be in 
for a shock if you compare it to an- 
other rig, Side by side, with the 
same LM386 audio driver, some 
QRP rigs are much louder. I noticed 
this several years ago at the annual 
Dayton HamVention QRP forum. 

We were playing with a new 
commercial rig. The audio was 
very wimpy. In fact, with a room 



full of people fixing the world's 
problems, you could hardly hear 
anything from the speaker. The 
guy who had just purchased the 
rig mentioned that the reason was 
the LM386. 'There's not much 
audio inside an LM386 " At that 
time someone looking over our 
shoulders said his rig had more 
than enough audio, so much in 
fact you could easily hear it in this 
room full of people. 

So, we connected his rig up to 
the same antenna. We tuned in a 
station on 40 meters. With the 
volume control up only to half- 
way, someone across the room 
yelled at us to "Turn that damn 
thing down so we can talk." In- 
deed, the LM386 in his rig was 
really spitting out the audio! 

Now, there are only so many 
ways you can configure a LM386 
audio amplifier. You can select the 
amount of gain produced by 
swapping out a capacitor* but you 
can't generate more gain than the 
device will produce. Since we 
were using the same antenna, that 
ruled out any gain produced by 
the RF section. Both rigs were 



based on a direct conversion re- 
ceiver, so almost all of the gain 
of the rig had to be in the audio 
chain. Everyone seemed to nar- 
row the difference down to audio 
preamplifiers before the LM386. 
That was several years ago. 
Here's some info I have since dug 
up about this unique chip. 

First, if you have a choice, get 
the LM386 made by National 
Semiconductor, Although the 
LM386 is made by a wad of com- 
panies, the National devices seem 
to work better 

Everyone Tve talked with has 
been under the that assumption 
the LM386 is a 1 watt audio am- 
plifier, hut it actually comes in a 
variety of different power levels. 
Fact is, some are rated for only 
300 m W [ You can tell by the num- 
ber on the chip. An LM386-1 is 
rated for 250 mW, the LM386-3 
is rated for 500 mW, while the 
LM386-4 is rated at 700 mW. 
National spec sheets say normal 
power output for this version is 
close to 1 ,000 mW. 

There are iwo other problems 
with LM386 designs. One is 



r: 



B+ 



3+ 




Maintuning/R2 



Key 



Open = RIT on 



y-ry 



to rig 




/ z 



To RIT 
board 



1k 



U 



Dual color LED 



B+ 



Fig. 1.WA1 YIH \s modified RIT circuit . 



73 Amateur Radio Today • February 1997 61 



over-driving the amplifier. This is 
a very common problem, espe- 
cially with home-brewed equip- 
ment. Let the gain of the amplifier 
do its job — you don't need to ap- 
ply 200 oi W of drive! Design 
your audio preamplifier so it pro- 
vides the proper level for the 
LM386. 

Another problem with some 
LM3S6 designs is a tendency to 
oscillate, or "motorboat." With 
rare exceptions, this can be cured 
by increasing the value of the 
decoupling capacitor on the VCC 
line of ihe LM386. It's also good 
practice to have this capacitor 
mounted as close as possible to 
the chip. Many designs show the 
value of ihis decoupling capaci- 
tor at about 220 pF. Increasing the 
value to 470 or 1,000 |iF will 
usually do the job. 

In really stubborn cases, a 
small value resistor, usually 10 or 
22 ohms, may be inserted in se- 
ries with the VCC line feeding the 
LM386. A 1/2 watt resistor should 
be used instead of the junk box 
1/4 watt device. 

An all-too-often overlooked 
item when fixing a wimpy 
LM386 is a poorly regulated 
power source. If your rig is run- 
ning from a battery, and there is 
an internal 7812 regulator feed- 
ing the LM386, the regulator 
won't have enough overhead to 
regulate. This will cause the volt- 
age supplying theLM386 to wan- 
der about. You can prevent this 
several ways. 

First s you can run the LM386 
from the input side of the regula- 
tor, assuming the input (supply) 
voltage is between 12 and 14 volts 
DC. 

If this is not possible, you can 
use a voltage regulator with a 



lower voltage rating, A 7810 will 
have the necessary overhead 
when using a 12 volt supply, but 
just barely! A 7808 would be 
ideal, provided your circuit will 
operate at 8 volts, There is a 7809, 
but it's hard to come by. 

If you need to increase the volt- 
age of a 7808 regulator, there are 
two fixes. First, you can put a di- 
ode in series with the ground pin. 
For each diode, you will raise the 
output by .7 volts. Or, you can use 
a resistor connected to the ground 
pin. In both cases, you raise the 
ground pin slightly above ground, 
which causes the output voltage 
to increase, i should mention that 
neither way is the preferred 
method to increase the voltage of 
a three-terminal regulator. It's al- 
ways best to specify the correct 
voltage regulator for the circuit 
under design, 

Last month's schematics 

Some of the schematics were 
missing from last month's col- 
umn. Moving into a micro apart- 
ment has really put the screws to 
me. As things begin to settle 
down, I'll be able to get back into 
my routine. If you are interested 
in some of the missing schemat- 
ics, drop me a line. Do be sure to 
send letters to my new address, 
P. (X Box 508, Massillon, Ohio 
44648. 

Out of all this madness, a 100 
percent solar home will be con- 
structed. A 4 k W peak solar array 
is planned. Also planned is a 65- 
foot free-standing tower, com- 
plete with some real antennas! 
The best part of it all is Lhat by 
the time Tin done, the sunspot 
cycle should be taking off. Talk 
about good timing! 



Letters 

Continued from page 60 

licensed as WN4ZFL and W4ZFL 
in Pensacola, FL, as a teenager, I 
teach foreign military personnel at 
the Defense Language Institute 
English Language Center at 
Lackland Af ■" Base and last week I 
was introduced to a Turkish AF of- 
ficer there who had an encounter 
with a UFO. About five years ago, 
he told me, he was in the front seat 
of an F-104 when his instructor in 
the back seat called his attention to 



an approaching disc-shaped bright 
light. It continued to approach 
them, and when it was quite close 
his instructor decided to initiate the 
ejection sequence. Before he was 
ejected, after being told to prepare 
for ejection in 10 seconds, he saw 
the UFO veer away from them, but 
too late to save the aircraft. The 
approach of the UFO to their air- 
craft was, fortunately for the pi- 
lots involved, witnessed by 
personnel in a control tower close 
to the runway. 



Specihl euents 



Number 62 on your Feedback card 



Listings are free of charge a$ space permits. Please send 
us your Special Event two months in advance of the issue 
you want it to appear in. For example, if you want it to 
appear in the June issue, we should receive it by March 31. 
Provide a clear, concise summary of the essential details 
about your Special Event 



FEB 8 

CHARLESTON, SC The 24th annual 
Charleston Harnfest and Computer 
Show will be held at Stall KS. near I- 
26 and Ashley Phosphate Rd. F in 
North Charleston. Tailgating allowed, 
Talk-In on the WA4USN Linked Rptr. 
Sys. 146.79(-) Rptr. aboard the USS 
Yorktown and the 1 45.25(-) Rptr. near 
Summerville. Tickets will be sold Sat. 
morning at the door; $5 for adults. 
Children under 12 admitted free. Pre- 
reg. tables am $8 per 8 ft, $10 at the 
door as long as they fast. Make check 
payable to C.A.R.S. Manifest 
Committee, and send with an 3ASE, 
to Jenny Myers WA4NGV. Table 
reservations must be receded before 
Jan, 24th- VE Exams on site starting at 
12 Noon. Walk-ins. Bring original and 
copy of your license, any CSCEs you 
have, and two IDs, one with a photo. 
For exam info, call Ed Frank KC400Z, 
610 Longstreet Qr tf Summen/life SC 
29483. Tei.(803) 871-4368; or Doc 
W4MUR f (803) 884-5614 or E-mail: 
efrank@charieston.net The Harnfest 
contact is Jenny Myers WA4NG V f 2630 
DettwoodAve,, Charleston SC 29405- 
6814. Tel (803) 747-2324, or E-mail: 
brycemyers@aol.com. VE Exams are 
also given monthly on each 3rd 
Saturday, at Trident Tech College, 
ReversAve,, North Charleston, Bldg.630 
at 9 AM. Contact Ed Frank KC400Z, 
(803) 871-4368. 

DEARBORN, Ml The Michigan 
Antique Radio Club will host its Swap 
Meet at the Armenian Hall on Ford Rd. 
Open to the public 8 AM-Noon. Adm. 
$2 per person. ASilent Auction, Equip. 
Contest, and a Donation Auction will 
be featured. Contact Jim Clark at 
(517)349-7187. 



Other DLIELC students have 
told me of UFO encounters over the 
years, While teaching all the mili- 
tary officers attached directly to the 
Colombian president (his personal 
pilot, security chief, protocol of- 
ficer, a Navy liaison officer, and the 
colonel in charge of "La Caaa 
Militar") a number of years ago at 
the Presidential Palace in Bogota, 
Colombia, I asked these officers 
one day when we were all together 



FEB 9 

MANSFIELD, OH The Mansfield 
Mid*Winter Hamfest/Gomputer 
show will be held by the InterCity 
ARC, Inc., at the Richland County 
Fairgrounds in Mansfield. Doors 
open at 7 AM Tickets S4 in advance, 
$5 at the door. Tables $9 in advance, 
$12 at the door k if available. 
Advance orders must be received 
and paid by Jan. 13th, Send 
requests, payments, and SASE to 
Pat Ackerman N8YOB, 63 N. Illinois 
Ave., Mansfield OH 44905; or phone 
(419) 589-7133 after 1 PM EST. 
Talk-\n on 146.34/.94 W8WE. 

FEB 13 and 27 

FORT WORTH, TX The Lockheed 
ARC and the Kilocycle Club of Ft. Worth 
will sponsor VE Exams for all classes 
at the Lockheed Rec. Area Facility 
located at 2400 Bryant Irvin Rd, Exams 
start at 7 PM. G.R.D.L testing done by 
appointment only. Call Ted Richard 
AB5QU at (81 7) 293-6745. 

FEB 14-16 

ORLANDO, FL The OARC of 
Orlando will host the Orlando 
HamCation and Computer Show, and 
ARRL North Florida Convention at 
Central Florida Fairgrounds. Set up 
Fri. 9 AM-5 PM; open to the public 
Fri. 5 PM-9 PM, swap tables only. 
Sat. 9 AM-5 PM and Sun. 9 ANM£ 
PM. 150 commercial exhibits. 
Largest tailgate area in FL, RV 
ovemite parking $16. Adm. $6 
advance, $9 gate. Free parking. 
Swap tables $25/Tailgate $1 5 all 
3 days. For advance tickets and info, 
contact Orlando HamCation. P.O. 



if they thought the most likely ex- 
planation for the more reliable, 
more substantial, credible reports 
was that we are being visited by 
extraterrestrials. Going around the 
conference table with this question 
I was fascinated when each officer 
responded with a "Yes" That's the 
only military group V vc taught over 
the past 30 years that was so unani- 
mous when asked such a question. 
Continued on page 81 



62 73 Amateur Radio Today - February 1997 



Box 547811, Orlando FL 32854. 
E-mail: kd4jqr@aQi.com* Web Page 
www.cycatcom/users/oarc. Forums: 
NASA Astronaut, SliaWFhoto Exhibit 
of Lightning Storms, ARRL, APRS 
Demo by Bob Bruninga, WX 
Downloads, WX Equip, for the 
Home, Shortwave Listening by Bob 
Grove, pub. Monitoring Times, Build 
a VHP SWR Meter; Grounding for 
Lightning; Antenna Workshop; 
Radio Testing, and more. 



15 



HAHRISBURG, PA The Hamsburg 
ARC w\\\ hold its Winter Manifest 8 
AM-Noon at the Oberlin Fire Hall, 
Oberiin PA. General adm, $2. inside 
Tables $3 ea. Tailgating $1 per 
space. Dealer Set up at 6 AM- VE 
Exams start at 9 AM. Talk-in on 
146.76. For info and table 
reservations, phone the HRAC 
Answertine at (717) 232-6087, 

HORSEHEADS, NY TTieARAof the 
Southern Tier will present a Hamf est 
at the New York State Armory, 128 
Colonial Dn, 7 AM-3 PM, There win 
be dealer displays of new equipment 
and an indoor Flea Market area. 
Tables will be available on a first-come 
basis. VE Exams start at 9 AM. 
Contact Jack Stocum, 410 
Shelbourne SL, Horseheads NY 
14845. Tel (607) 739-4866. 

TRAVERSE CfTY, Ml ChenylandARC 
will hold their 24th annual Swap-n-Shop 
at Immaculate Conception Middle 
School, 8 AM-Noon. VE Exams 
following the Swap at t and 4 PM Talk- 
in on 146.36. For more details call Joe 
W8TVT at (616) 947-8555, or Chuck 
W8SGRa\ (616) 946-5312. 

FEB 16 

BRIGHTON, CO The Aurora Rplr. 
Assn, will hold its 15th annual 
Swapfest at the Adams County 
Fairgrounds, 9755 Henderson 
Rd,, 8:30 AM-2 PM. For details, 
contact Chris Knauer KB9CCR, 
(303) 403-1883; or E-mail at 
cknauer@$kywam,org; or write to 
Aurora Repeater Assn., c/o Janice 
Ghristopherson, 4376 $, Argonne 
Way, Aurora CO 80015. 

NEW WESTMINSTER, BC t 
CANADA The Burnaby ARC, 
VE7RBY will hold the "Bumaby ARC 
10th Annual Fleamarkef at New 
Westminster Armounes, 6th St. and 
Queens Ave., 10 AM-2 PM. Set up at 
9 AM. Talk-in on VE7RBY 145.35B 
or 442.85. For info and tables, phone 
between 7 PM-9 PM PT: Harry 
VE7HNC, (604) 530-3962; Graham 
VE7ABC, (604) 530-1907; packet 



VE7ABC&VE7KIT; or Rick VE7HRL, 
(604) 464-0768. 

FEB 22 

LAPORTE, IN The LaPorte ARC 
"Cabin Fever Hamfesr will be held 8 
j AM-2 PM at LaPorte Civic Center. 
Adm, $4; tables $5 ea. Talk-In on 
K9JSI 146.610 (131.8PL), 443,900 
(131 .8PL) and 146.520 simplex. For 
details contact John N9ROH, LPARC, 
PC Box 30 t LaPorte IN 46352. 

MILTON, VT The Ratio Amateurs of 
Northern Vermont will sponsor the 
Northern Vermont Winter Hamfest 8 
AM-3 PM at Milton H.S., Route 7. 
Features include Flea Market, 
Auction, Dealers, Book Sales, 
Forums, and more. VE Exams will be 
given at 9 AM and 2 PM. Commercial 
Exams at 2 PM, Adm, $3, free for 
under 18 years. Tables are free while 
they last. Call for Large setups. TaJk-in 
on 145.15 RptL Contact W1SJ 
at (802) 879-6589. E-Mail: 
wb2j$j@vbi,champiajn t edu. Web Site: 
h ttp://www. together net/- fflynn/ 
miltonMtnit* 

FEB 23 

CUYAHOGA FALLS, OH The 

Cuyahoga Falls ARC will host its 43rd 
annual Hamfest at Emidio's Party 
Center, 48 Bath Rd. f 8AM-2 PM, Free 
parking. Talk-in on 147.87/.27 
W8VPV. Adm. $4 advance, $5 at the 
door. Reserve tables by Feb. 8th, 
$8 advance, $10 at the door, if 
available. Contact Bob Recny 
N8SQT, 496 Orlando Ave. , Akron OH 
44320-1243. Tel. (330) 664-581 0; 
FAX (330) 864 5879; E-mail: hamfest 
@ neo.irun.com. 

LIVONIA, Ml The Livonia ARC will 
present its 27th annual Swap *n' Shop t 
8 AM-3 PM, at the Dearborn Civic 
Center, Deaibom Mi. VE Exams. Talk- 
in on 144.75/.35. For info, send a 4x9 
SASE c/o Neit Coffin WA8GWL, 
Livonia ARC, P.O. Box51532 t Livonia 
Mt 48151-5532; or call the Club 
Phone Line, (313) 261-5486. 

MAR1 

ABSECON, NJ The Shore Points 
ARC will sponsor its 15th annual 
hamfest "Springiest 'ST at Holy Spirit 
H.S. on Route 9 T starting at 8 AM. Set 
up at 6:30 AM. Flea Market, outdoor 
Tailgating (weather permitting). Talk- 
in on 146.385/.985 PL 146.2 Hz, For 
info, write to SPARC, P.O. Box 142, 
Absecon NJ 08201- or cal/FAX (609) 
653-1987. 

PARSIPPANY, NJ The annual North 
Jersey Hamfest, sponsored by Split 



Rock/West Morris Radio Clubs will 
be held at the PAL Bldg. on Smith 
Rd. Talk-In on 146.985/.3B5. For info 
or reservations, call Bemie 
WB2YOK, Fax/Voice (201) $84- 
5399 24 hr$.; Online 75503 
,322 W CompuServe .com. 

MAR If 

KNOXVILLE, TN The Shrinere of the 
Kerbela AR Service will sponsor the 
Kerbela Hamfest at the Kerbela 
Shrine Temple, 8AM-4 PM. Adm. $5. 
Indoor vendor tables $8 ea,. plus 
adm.; outdoor tailgating spaces are 
$3 plus adm. Set up at 4 PM-9 PM 
Fri, and 5 AM-8 AM Sat. Talk-in on 
144.83/145.43, or 146.52 simplex. 
Smoking in designated area only. 
Contact Paul Baird K3PB, 1500 
Coulter Shoais Circle, Lenoir City TN 
37772. Tel. (423) 986-9562. 

SPECIAL EVENT STATIONS 

FEB&-10 

ST PETERSBURG, FL The QCWA 
Golden Anniversary QSO Party will be 
open to all Amateur Operators, world 
wide, 1400 UTC Feb. 8th -0600 UTC 
Feb. 10th; and 1400 UTC Mar. 6th- 



0600 UTC Mar. 10th. For rules, send 
request and a business size SASE to J. 
Fmderick Strom K9BSI, Activities Mgr., 
233 34m Ave. North, St. Petersburg FL 
33704-2241. All logs must be received 
no later than Apr. 1st, 1997. Mai Feb. 
logs to Arthur Atonsees W4BK 420 Bay 
Ave, Apt 1521, Clearwater FL 34616. 
Mai Mar, togs to Donald Btce W4PCO t 
5511 18th Ave. North, St. Petersburg FL 
33710. 

FEB 14, 15, 16 

MARQUETTE, Ml Hiawatha ARC 
K8LOO Up 200 Sled Dog Race. 20- 
80 meters, General. For a certificate, 
send an SASE to N8BGA, 21 Smith 
Lane, Marquette Mt 49855. 

FEB 15-16 

ALEXANDRIA, VA The Mount Vernon 
ARC win operate K4EC 160G2-22QOZ 
Feb. 15-16 to commemofate George 
Washington's birthday. Operation wi be 
ii tie lower General 80-1 5 meter phone 
subbands and ii the Novice 10 meter 
subband. For a certificate, send your 
QSLanda9x12SASEto MVARC, P.O. 
Box 7234 f Alexandria VA 22307. For 
more Information, contact Mary Pat 
Nowack KE4QWK t 703-684*8793. 



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73 Amateur Radio Today • February 1997 63 



ytafft 



fla* 



Number 64 on your feedback cartf 



puo 



Communications Simplified, 

Part 14 



Although we can calculate the 
VSWR once we know the load 
impedance, in practice it is a lot 
easier to measure it directly. The two 
most common instruments used are an 
inexpensive SWR bridge and a much 
more expensive (and more accurate) de- 
vice called a through-line wattmeter 
The Bird Thru Line meter is the most 
common brand name of the latter. Both 
of these work on pretty much the same 
principle; Fig. 1 shows how the SWR 
bridge works. 

The meter has a metal trough running 
from one end of the case to the other, 
with the transmitter and antenna connec- 
tors at opposite ends of the case. Run- 
ning through the trough are the three 
wires labeled A, B, and C in Fig, 1, 

Wire A carries the signal from the 
transmitter to the antenna. Wires B and 
C are close to it, but not touching; they 
are called sensing wires. 

Let's look at wire B first. Because B is 
right next to A, there is a small capaci- 
tance between the two. This causes wire 
B to pick up a small amount of signal 



from A. But as current goes through wire 
A to the antenna, it also generates a 
small magnetic field. Wire B is in that 
field, and therefore picks up a small 
amount of signal from the magnetic field 
as well. The polarity of the signal picked 
up through the capacitance docs not de- 
pend much on which way the signal is 
going, but the polarity of the inductively 
coupled signal does, For an outgoing 
signal from the transmitter to the an- 
tenna, the two voltages add, whereas for 
the reflected signal, they cancel. Diode 
Dl therefore gets a signal proportional 
to the outgoing or forward signal, but ig- 
nores the voliagc from the reflected sig- 
nal. In the same way, diode D2 gets a 
signal proportional to the rclleeicd sig- 
nal. The two voltages are then rectified 
and filtered by the two diodes and ca- 
pacitors, and fed through the FWD-REV 
switch to the meter. 

The secret to the measurement is in 
the meter's scale calibration, shown in 
Fig, 2, To use the meter, we first connect 
it to the transmitter, set the FWD-REV 
switch to the FWD or Forward position 



Peter A, Stark K20 AW 

P.O. Box 209 

MtKiSCONY 10549 




Fig. 2, SWR bridge meter settle* 

and turn on the transmitter. Then we set 
the CAUbrate control so that the meter 
reads full-scale; there is usually a small 
SET mark at the right end of the scale. 
Regardless of how much power or volt- 
age the transmitter is sending out, this 
calibrates the SWR bridge to that level. 
The next step is to switch the FWD- 
REV switch to the REVerse setting 
{without touching the CALibrate con- 
trol). If all of the power is reflected from 
the antenna, indicating an infinite 
VSWR, the reverse voltage is the same 
as the forward voltage, and thus the 
meter will read full-scale. So the full- 
scale end of the scale reads infinity. If, 
on the other hand, the antenna is a per- 
fect match, then the reverse voltage is 
zero and the VSWR is 1 ; hence the left 
end of the scale reads 1 . 



From 
transmitter 



A 




B 






C 





To 
antenna 



LS£J7L 



Rev CAL 




Meter 



Fig. 1. An SWR bridge. 

64 73 Amateur Radio Today • February 1 997 



At the midpoint the reverse voltage is 
exactly half of the forward or outgoing 
voltage. For example, if the outgoing 

signal is 10 volts and the reverse is 5 
volts, the VSWR is then: 



VSWR = 



I 



Vniax 
Vmtn 



+ 5 15 

10 - 5 " 5 ~* 



so the midpoint reads 3. Since VSWR 
above 3 is generally considered quite 
bad, the right half of the scale is usually 
colored red, 

A typical SWR bridge costs $20430. 
and covers a fairly limited frequency 
range. For more accurate measurements. 
many professionals use the Bird ThruLine 
Wattmeter. This meter works on the same 
principle, but instead of having two sepa- 
rate sensing wires, two diodes, and a 
switch to select them, there is one sensing 
wire and its diode, mounted in a rotating 
assembly called a slu# t The slug has a 
printed arrow on it, and you rotate it to 
measure the forward or reverse voltage. 
The meter is calibrated in watts, rather 
than in VSWR. Because the reading de- 
pends on frequency and power. Bird 
makes several dozen different slugs for 
various power and frequency ranges. This 
makes the power readings quite accurate, 
but the disadvantage is that you have to 
calculate your own VSWR from the for- 
ward and reverse power readings. (In prac- 
tice, many technicians take the easy way. 
If the forward power is "big" and the re- 
verse power is "small," then they are 
happy!) 

One application —a waveguide 

The idea that a line shorted at one end 
can appear open at the other, and vice 
versa, has some interesting applications. 
Consider microwaves, for instance. 

Microwaves are radio waves thai have a 
very high frequency, typically more than 
several gigahertz. This also means that 
they have a very 1 small (micro) wave- 
length. For example, a signal at 10 GHz 
has a wavelength of ahoui 1/4". At these 
frequencies, signals travel only on the sur- 
face of wires, not inside them: this is the 
so-called skin effect. A much more severe 
problem is that most insulators do not 




Fig. 3. Making a waveguide. 

work very well at these frequencies- — they 
are too lossy. So it is difficult to build a 
cable to cany them any great distance. 

But suppose you used a pair of 
uninsulated wires (A and B in Fig. 3) held 
up by a wire loop, as shown at the left of 
the figure. If the wire loop was exactly 1/4 
wavelength long, then its lop would ap- 
pear open even though the bottom is 
shorted. In other words, a perfect insulator 
made of metal! 

In practice, this is a lad tough to fabri- 
cate. But since you can place these wire 
loops as close together as you want, there 
is no reason why they cannot be made into 
the continuous trough shown as C in Fig, 
3. To prevent rainwater from collecting in- 
side, we place another identical trough (D) 
above it, giving us a rectangular pipe 
called a waveguide. The signal simply 
travels along the inside edge of the pipe, 
aujghly in the middle of the long side, 
which is now 1/2 wavelength long (1/4 
wavelength from the middle toward each 
end). 

The frequency at which the long side of 
the waveguide is exactly a hull- wave- 
length long is called the critical frequency. 
Frequencies lower than the critical fre- 
quency can't make it through the 
waveguide because the distance from the 
midpoint to the edge is too small — they 
get shorted out by the edge of the loop. But 
frequencies above the critical frequency 
can make il through, simply by traveling a 
bit closer lo the edge. 

Most waveguides are fairly small. But if 
you've ever driven through a long tunnel, 
you've been inside a large waveguide. You 
may have noticed that your AM radio goes 
dead almost as soon as you enter the tun- 
nel, whereas your FM radio only gradually 
fades out as you go in, The reason is that 
Ihe typical tunnel is tin) small to let AM 



broadcast signals through. Since the typi- 
cal AM station has a wavelength of 600 
feet or more, the tunnel would need to be 
more than 300 feet (a half wavelength) in 
diameter to let the signal in. So AM signals 
simply don't make it into the tunnel. FM 
broadcast station frequencies, on the other 
hand, have a wavelength of about 10 feet, 
so even the smallest tunnel will let them 
through. 

Tunnels don't really make good 
waveguides, though, because they are not 
made of a good conductor. Underwater 
tunnels are made from short sections of 
steel pipes, with waterproofing compound 
joining them so they do not leak. This wa- 
terproofing insulates the sections from 
each other, so FM signals, though they get 
partway into the tunnel, cannot really 
travel all the way through. Still, it makes 
an interesting example. 

The idea of radio waves getting through 
holes is similar. For example, if you 
wanted to shield a room to prevent radio 
waves from getting in or out, \ou could 
completely encase it in a solid sheet of 
copper But this isn't necessary — you can 
use copper sheet with holes in it, as long as 
the holes arc substantially smaller than 1/2 
wavelength. Likewise, the metal sheet 
covering the window in a microwave oven 
door has holes that we can sec through. 
But the holes arc much smaller than the 
microwave wavelength, and so the 
microwave energy cannoi get through. 



Another application— a stub 

A stub is simply a short piece of 
transmission line. For example, sup- 
pose you are trying to receive a par- 
ticular station, hut another strong 
nearby station is causing interference 
in your receiver. You therefore decide 
to filter out the interfering station and 
keep it out of your receiver. 

The simplest (though not necessarily 
die best) solution is to connect a 1/4- 
waveleagth stub in parallel with your 
receive antenna. If you leave the far 
end open, ihe end connected to your 
antenna terminals will act as a short 
and short out the interfering signal. 
You must keep in mind the velocity 
factor of the cable to calculate the cor- 
rect length; in practice, it's probably a 
good idea to cut the cable a bit too 
long, and then cut off tiny pieces while 
observing ihe interference, until the 
length is just right. 

73 Amateur Radio Today • February 1 997 65 



Transformers for impedance matching 

Quite often you need to match one im- 
pedance (for example, a 75-ohm cable) to 
another (such as a 300-ohm antenna). This 
particular case is a common one with TV 
antennas; many TV antennas are designed 
for 300-ohm twin-lead, but used with 
75-ohm coax cable. 

In this example, there is more than just 
impedance matching at stake. Coax cable 
is unbalanced (the signal travels on the in- 
ner wire, while the outer shield should be 
at ground potential), whereas most TV an- 
tennas are balanced (both connections 
carry the signal, but out of phase with each 
other.) Such transformers are also often 
called baluns, because they connect be- 
tween a balanced and an unbalanced 
device. 

Matching transformers are readily avail- 
able just for this purpose. The ones for TV 
use are cheap because only low power is 
involved; the ones for transmitting appli- 
cations must handle the full transmitter 
power and so they are bigger and more 
expensive. 

Fig. 4 shows the wiring of a typical TV 
balun transformer designed to match 75- 
ohm coax to a 300-ohm balanced antenna. 
The transformer consists of two wire 
windings, wound near or over each other. 
Since the impedance ratio of the two wind- 
ings of a transformer is the square of the 
turns ratio (the ratio of the number of turns 
on the primary and secondary), for a 300- 
to-75-ohm impedance match (a ratio of 4- 
to-1), we need a turns ratio of 2-to-L So 
the 300-ohm side of the transformer has 
twice as many turns as the 75-ohm side. 

The matching transformer in Fig* 4 
has the advantage of being usable over a 
wide range of frequencies, But if you 
only need to match at one specific fre- 
quency, you can use a length of 
transmission line instead. 



We've now learned that a 1/4- wave- 
length cable can change a short into an 
open, or vice versa. But there's more to it 
than that. If the characteristic impedance 
of the cable is Z c and the load on its output 
is Z hjad , then the impedance Z^ you see 
looking into the cable is: 



^in - 



Zo 2 



Notice that this makes sense: if Z. A is 
an open (infinite impedance), then Z. n is 
a short (zero impedance). If Z |tiad is a 
short (zero impedance), then Z_ n is an 
open (infinite impedance). And if Z toad is 
equal to Z_, then Z is also Z_, So far so 

1 en 

good. 

But we can take this equation and 
rewrite it as: 



Z<? - Z>load X Z//2 



TLq = vZioad X Z 



m 



So if we want to connect a load Z, , of 



load 



300 ohms to a 75-ohm input Z , all we 
have to do is connect a 1/4- wavelength 
line between them whose characteristic 
impedance is: 



z o= ^load x Zin = VSOO X 75 



= 150 ohms 



With the 300-ohm load on a 1/4-wave 
section of line having a 150-ohm charac- 
teristic impedance, the input into the line 
will look like 75 ohms, a perfect match. 



75-ohm unbalanced 




»««wt«»«»«tt w ;i i iiHi :m i i Pi;i HM Bi i M«to«H irt iM«tafc ft iii»Mi4i 





300-ohm 
balanced 



1:2 
turns ratio 



f7#. 4. 300-7 5-ohm hatun. 

66 73 Amateur Radio Today • February 1997 



There are two catches, of course — this 
will only work at the one frequency that 
the line is cut for, and you cannot mix a 
balanced line with an unbalanced line, So 
this is totally unusable for (he typical TV 
application. But it is perfectly suited for 
those single-frequency applications in 
communications. 

Last thoughts 

There is one other idea that should be cov- 
ered, but that didn't somehow fit into any of 
the previous sections. In a balanced transmis- 
sion hue (such as the 300-ohm twin lead used 
in TV antennas), it's obvious that the signal 
travels along both conductors. But many 
people believe that in coax the entire signal 
travels only along the inside conductor, and 
the shield is there only for the ride, so to 
speak — to keep outside signals out and 
inside signals in. Not so, 

If you place a load, such as a resistor, at the 
end of a line, the only way to get a current to 
flow in the resistor is to have both ends of it 
connected to something. Whatever current 
flows into the resistor from the center con- 
ductor must flow out the other end, m<\ into 
the shield. So the shield takes an active part in 
the process. This will be an important concept 
in the next article in this series, when we talk 
about antennas. An antenna cannot connect 
just to the center conductor of the coax be- 
cause then the current has nowheir to go. 
There must be a solid connection from the 
coax shield to some active part of the antenna 
so that current can return along the shield, 

Summary 

Our treatment of transmission lines 
has been a very brief, simplified one. 
There's a lot more to this subject. For 
one thing, we've assumed that our trans- 
mission lines have no loss. That's not 
true; the loss changes the results some- 
what, and usually must be taken into 
account. 

More important, even though we've 
used the symbol Z in our calculations to 
keep things general (and to use the same 
symbols as most other books and ar- 
ticles), we've ignored the fact that these 
are really impedances — we*ve made be- 
lieve that all the Z's have been pure re- 
sistances. That makes things simple, 
but is not exactly realistic. But at this 
point I will use the standard excuse 
you'll find in many books: "More ad- 
vanced treatment is beyond the scope 
of this article." 



Number 67 on your Feedback card 



QRP T-R Circuit 



It's simple and versatile. 



Mark L. Meyer WU0L 

14153 West First Drive 

Golden CO 80401 



Have you been looking for a 
simple T-R circuit for your QRP 
transceiver project? I loo was 
faced with this problem recently. I 
wanted something that was simple, 
would work for several different bands, 
and would not add significantly to 
battery drain. 

Most of the current crop of QRP de- 
signs and kits are of the single-band va- 
riety and use the L-C scries traps method 
of automatically isolating the receiver 
input from the antenna when the trans- 
mitter is keyed. This is a great and 
simple method; however, the L-C net- 
work is specific for each separate band. I 
was working on a multibander so I 
wanted a circuit that would work for all 
bands without modification or duplica- 
tion. I also wanted near QSK perfor- 
mance for quick changeover, not 
between CW characters but between 
words or pauses. I decided what I really 
needed was a reed relay circuit that 
would utilize a normally closed contact 
to keep the antenna connected to the re- 
ceiver with no current flow at all during 
receive periods. 

Reed relays have very fast switching 
times and also have high coil resistance. 
This means low current flow, especially 
compared to what a rig draws anyway on 
transmit. These relays typically draw 
only 15 milliamperes or less operated at 
12VDC. 

The circuit 

Fig. 1 shows the circuit I developed. 
The circuit is activated from the key line 
on your rig. This is the line that goes to 
ground potential when your rig is keyed. 
This comes straight from your key jack; 
either your hand key or your kcyer, when 



activated, causes this line to go to ground. 
This in turn causes a keying transistor to 
turn on, applying 12 volts to various pans 
of your transmitter circuitry. 

In Fig. 1, nearly the same thing hap- 
pens as in your transmitter. When A is 
grounded, Ql turns on. This applies +12 
volts to the coil of RLY1 . Since this is a 
very fast relay, it immediately opens the 
contact separating the receiver from the 
antenna. Note that the Ql circuit does 
not contain any timing or shaping ca- 
pacitors like your switching transistor in 
your transmitter circuit does. This is be- 
cause we want RLY I to pick up immedi- 
ately before the transmitter is turned on. 
Otherwise we may pump some transmit- 
ter power into the receiver, causing some 
serious problems! 






Ql also applies voltage to capacitor CI 
through resistor Rl, causing it to charge. 
This is the dropout timing circuit. When 
Ql returns to normal, CI discharges 

through R 1 and the relay coil C 1 and Rl arc 
chosen to keep the relay pulled in through a 
normal string of dits and dahs, but to drop out 
on pauses or between words. 

If you wish a longer dropout period, 
simply increase CI to 330 ^UF or 470 |iR 
Reduce CI for a quicker QSK type re- 
sponse. RTs purpose is to make sure that 
RLY I receives full voltage immediately 
(not dragged down by charging CI) upon 
energization, so pickup is quick. 

The relay 

The relay specified has a 1,000 ohm 



R2: I OK 



A 

o 



R3i 15K 



B 




+12VDC 



Keyed Line 
Grd to Activate 



Ql:2N390o 



Dl: IN914 



*R1: 100 



CI: 220 \if 




> 



TO LOW 
PASS FILTER 



N.C. 



* Adjust tu increase/decrease 
time delay to dropout 



> 



TO RCVR 
INPUT 



y 7 



Fig. l.T-R antenna changeover circuit. 



73 Amateur Radio Today * February 1997 67 





i£? 



\ 




Photo A, The T-R hoard shown before 
installation, resting on top of the case for 
the rig. 

coil. Energized, it will draw about 12 
mi Hi amperes. I am currently using a re- 
lay with a coil that measures 800 ohms 
and the values specified are right for my 
normal keying speeds. Feel free to ex- 
periment with whatever relay you chose 
by varying CI and Rl, but do not lower 
Rl very much because you want RLY1 
to pick up immediately, 

A word about reed relays— they come 
a several different forms. Most have one 
normally open contact. You want one 



with a normally closed contact for this 
circuit, so check it out with your ohm- 
meter. Also, some reed relays have a 
built-in suppression diode (D2). In this 
case you don't need to include D2 in 
your circuit (but it won't hurt if you are 
unsure). D2 provides a safe path for the 
energy stored in the coil to dissipate 
when the coil is de-energized. Some 
reed relays are polarized. Be sure the (+) 
mark is towards Ql if the relay you use 
has a polarizing mark. 

Test your relay by connecting your 
ohmmeter across the contacts and ener- 
gizing the coil from a 12 volt supply. 
Watch for polarity before you connect 
the coil to the supply. When you ener- 
gize, the contact should open and the 
meter reading go from zero to infinity. 

Reed relays have long life expectan- 
cies. The relay specified is good for 100 
million operations when switched dry. 
(That dry means when the contacts do 
not have to switch current other than 
very small signal values, like we are do- 
ing,} For the worst-case scenario, if you 
transmitted 24 hours straight every day 
for an entire year, at 15 wpm, using full 
QSK, you would just barely exceed 100 
million operations. For us less active 




Photo B. The T-R Board (upper center) installed in a portable rig. Directly below are the PA 
and driver boards. The low-pass filter is located on a board underneath the T-R board. 

68 73 Amateur Radio Today * February 1997 




ANT 



RF 

FINAL 

AMP 



MATCHING 
TRANS. 



KCVK 

INPUT 



LOW PASS 
FCLTEK 



ANTENNA 
\ CHANGE-OVER 
CIRCUIT 



Fig. 2. Hookup. 

operators, this relay should have a long 
life span. 

Construction and testing 

All parts other than the relay are gar- 
den variety. Just about any small PNP 
silicon switching or small signal transis- 
tor will work for Ql . The diodes are sili- 
con small signal or even small rectifier 
diodes, CI should have a 25 volt rating 
to be sate. 

I built my T-R circuit on a little scrap 
of printed circuit board measuring about 
2 inches by 1 inch, I just gouged out 
some isolated pads for each connection 
pad and drilled holes with my Drcmel ™ 
tool. A small perfboard or Radio 
Shack™ pre-drilled project board (RS 
#276-159) will work great. The Radio 
Shack board will accept the relay pins 
directly, making things easy. 

Hookup and testing are easy. Connect 
a 12 volt supply to the circuit. Again 
hook up the ohmmeter across the con- 
tacts. Ground "A" and see that the con- 
tact opens immediately but closes back 
after a short delay. You will need an ana- 
log ohmmeter to see the pickup and de- 
lay because most digital meters take a 
while for the reading to change. Then 
hook a jumper from your key line in 
your rig to "A." Send a string of dots and 
dashes. You should aim to have the relay 
stay picked up between characters but to 
drop out on pauses. If your operating 
habit is such that you would like the re- 
lay to hang in between words, increase 
CI substantially. Otherwise small 
changes will take care of things. 

Be sure that when messing with your 
rig you have a dummy load connected or 
you remove the 12 volt supply from the 
output transistor. You wouldn't want to 
blow r up the final because you didn't 
have an antenna connected. Now build 
the circuit into your transceiver. Connect 
one side of the relay contact to the spot 
between your low-pass filter and the 



power amplifier matching transformer, 
or between the low-pass Filter and the 
power amplifier itself if no matching 
transformer is used. The other side goes 
to the receiver input* That's it! 

You now have a very simple circuit 
that works great. It works for any of the 
HE bands without modification, and you 
learned a little about circuit design in the 
process. 



Parts List 


Relay 


RLY1 


Reed relay with 
Normally 

Closed contact 


Newark 
#65F2276 Or 
Mouse r #433- 
D31B510 


Diodes 


D1.D2 


General 
purpose 


1N914of 

1N4148 


Resistors 


R1,R2 f R3 


1.4 watt 




Transistor 


Q1 


Any small 
general 
purpose PIMP 


2N3906 


Capatilor 


C1 


£20 uF, 25V 





Elegant Rotating— Revisited 

Continued from page 20 



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r^i.-.-rir-i-rfh-'c 

. '.-:■-, ■'.■ 



: ■:-. 



"rv Aift ' 



IL' l .i,L-!.?'UJJ! 



^W^^^T^^^iiii '■'■■! ir ii ■■■■ ■■ nil ii ■ <ii i ■ ' i — i— i— —i — i— i — 

■ 



1 rm m m m v 









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I 



■ " . .. I - \ .!.-'■■ , ■ 

» ■ mv \.wi ii ■_ d-.-!-. hd 





r ft"' 

:■■•'■. :.V-:,", : :- ■ *A 
L ■' . 

Vn ■ 
nil 



:■; 
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Sr 

1 






I ft 1 Wife 






: -- 



sqj^^V Soto's j § 






£8 1 1 



07 






1 



ST 

1 










y 



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1 1 1 Pi 



M^ 1 



i*hi.i; 






.1 



Bjf f ^ s^tgU glial iH^ 



rr- ■ 5_ * J 1 7i ' 






^ ■ — ■ — — 



Fig. 7. Component side of the power supply board 
and placement of the components (not to scale). 



73 Wants your feedback •••we've been improving 73 for the past months 
with more articles, easier reading type, etc, And honestly, we need your feedback 
(in detail) if you have any critique either for or against the subtle changes that 
we've made. We know we can't please everyone every time, but if you tell us what 
you want 73 to be, we'll at least try to head in the direction for further "improvements" 
that might be mos t appealing to you. Thanks. 



Parts tor Aimer Board 


R1 


25k linear pot 


Rl^RMpRig, R21.R22 


1k, 1/4 watt 


R2, R11.R13, R1S, R2Q 


10k, iMwatt 


R16. R17 


15k, MA watt 


R10.R15 


75k, 1/4 watt 


R3, Re 


100k, 1/4 watt 


R4, RS 


1 meg, 1/4 watt 


R7, RB 


20kPCBpot 


R9 


1 meg PCS pot 


C1 


22 pF, 25 volt 


02 


5 pF, 25 vott 


01 . DZ, D3, D4 


1N314 


06 h D6 


LEDs, any odor 


IC1, IC2, IC3 


LM311 


Qt,Q2.Q3 


2N5222 NPN trans. 


K1.K2 P K3 


Radio Shack #275-£t4 4PDT relay, 
12 VDC coif 


J1 -J9 


Wire jumpers 


Parts for Power Supply and Audio Oscillator 


TR1 


12 vollS. 300 mA, AS #273-1305 


Voltage rsgyiator 


+12 volts, 7@12 


Voltage regulator 


-12 VOltS, 7912 


D7,DB 


1N4001 50PIV 


C3,C4 


1,000 |iF, 25 votts 


IC4 


LM555 


CS,C6 


0,1 |iF 


C7 


0.1 jiF h 25 volts 


ce 


10 pF, 25 volts 


Miscellaneous Parts 


\m amp fuse and holder, appropriate switch and power cord 



Neuer snv DIE 

Continued from page 55 

64- page book of 60 of my edito- 
rial segments which hadn't yet 
been in 73. 

All this got started with my 
first RTTY newsletter, 45 ye&rs 
ago. I was inspired by the John 
Campbell W2ZGU editorials in 
Analog. Well, it used to be As- 
tounding Stories. Unlike any 
other magazine I've seen, John 
wrote long editorials about any- 
thing he thought the readers 
might find interesting, I started 
reading his editorials around 
1938, when I got interested in 
science fiction. Unfortunately 
John smoked, so he died rela- 
tively young, robbing the world 
of a lot of entertainment. If you 
find yourself near an antiquarian 
book store, look for a 1966 
Doubleday book of John's col- 
lected editorials. You'll treasure 
it. 

As John wrote in his March 
1965 editorial, "Editorially I 
shall continue to try to investi- 
gate the nature of the stuffing in 
any suspiciously bulging shim 
around. My business is directly 
concerned with the progress and 
achievement of the human race; 



any orthodoxy that tends to side- 
track or otherwise impede progress 
is interfering with my business, and 
Til do what I can to sabotage 
them." You could do worse than 
follow in his footsteps. Just be- 
cause a lot of people believe 
something doesn't make it true. 
In fact, the likelihood is that it 
isn't true. 

Are you still just sitting there? 
Get cracking! Let's see what you 
can do. But please be sure to do 
your homework before you 
write. Know what you are 
writing about. 

Placebos 

Back when cortisone first be- 
came available an arthritis pa- 
tient pleaded with her doctor to 
let her have some. The doctor 
said that, well, cortisone was 
hard to get, but he had a new 
remedy that was supposed to be 
almost as good. For four weeks 
he gave her cortisone shots, tell- 
ing her it was the new remedy. 
She showed no improvement. 
Then he said that the cortisone 
had finally come in and showed 
her the ampule. But he switched 
to a sterile saline solution for her 
Continued on page 77 



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73 Amateur Radio Today • February 1 997 69 



Number 7Q on your Feedback card 



In Search of Higher Power 



and a safe connect ion for it. 



Robert W, Vreeland W6YBT 

45 May wood Dr. 

San Francisco CA94127 



eecnlly I saw an ad ibr a neat 
little 500 watt PEP mobile am- 
plifier. It looked like a great way 10 
get in some really high powered 75 meter 
mobile. Then I thought about how I would 
get power from the car battery to the ampli- 
fier, which required 13.8 volts at 80 amps 
peak. Supposing that the total resistance ol 
the cables plus contact resistance was 0.02 
ohms (not an unreasonable assumption h the 



MOSFETJs 

Probably the first really good RF power 
transistors were made by the Amperes divi- 
sion of Phillips, With a 28 volt supply, their 
BLX14 put out 50 watts PEP. The BLX15 
put out an astounding 150 watts using a 50 
volt power source. 

Most manufacturers saw more money in 
the 12 volt mobile market and neglected the 



"Most manufacturers saw more money in the 12 volt mobile 
market and neglected the high voltage high efficiency field/ 9 



peak IR drop would then be 80 times 0.02, or 
1 ,6 volts. This would leave 1 3.8 minus 1 .6, or 
12.2 volts to power the amplifier, not good, 
but I could probably live with it 

Next I thought about the FR power Tost in 
the cables and connections. It would be 80 2 
times 0.02, or 128 watts! This might even 
start a fire. The problem is not with the 
amplifier, but rather with the method of con- 
necting it to power. Obviously, high power 
12 volt equipment requires special care in 
installation. 

Hie Options 

What about a solid-state 120 volt powered 
linear for home use?There are several on the 
market, but they are all very expensive. One 
in particular caught my eye. It is rated at a full 

kilowatt output at 100 percent duly. What a 
beautiful unit! In enter to achieve such high 
output, they used 48 separate MOSFETs. No 
wonder it costs well over $4,000. 

There arc a number of vacuum tube lincars 
in the under-$2,000 price class, What do the 
vacuum tube people know that the solid-state 
manufacturers may not? More than 50 years 
ago they learned that the way to increase out- 
put is to raise the voltage, not the current. 
High current means high component losses. 

70 73 Amateur Radio Today » February 1997 



high voltage high efficiency field but at least 
one manufacturer has introduced a line 
of high power RF MOSFETS designed 
for use with a 50 volt supply. This is defi- 
nitely a step in the right direction. The catch 
is that inside what looks like a single transis- 
tor there is a whole bunch of separate 
MOSFETs, each with its own gate and source 
connecting wires — a very expensive type of 
construction. 

What about really high voltage 
MOSFETs? There are 600 and even 800 
volt models available. They are used in 
low frequency switching applications. The 
problem is that they are generally not de- 
signed for RF use. They usually have very 
high input and output capacitances and a 
slow rise lime. Well, not always. A com- 
pany called Supertex (1235 Bordeaux 
Drive, Sunnyvale, CA 94089) has devel- 
oped a proprietary process whereby they 
can reduce the capacitances and the rise 
time. Although they are not in the really 
high powered transistor business, they 
have a couple of 6(H) volt MOSFETs that 
offer exciting possibilities. These are the 
VN0360N1 and the VN0660N5. I have 
used the VN0360N 1 in an amplifier for 80, 
40, and 20 meters', For improved 



performance on 20 meters, I used the 
VN0660N5. It is a somewhat lower pow- 
ered device with a better rise time and 
lower capacitances. 

One nice thing about 6(X) volt 
MOSFETs is that they are high impedance 
devices and are therefore suitable for use 
in tuned amplifiers. Another advantage is 
that they can be powered by the rectified 
and filtered 120 volt line without the need 
for a power transformer. My 20 meter am- 
plifier uses a pair of VN0660N5s in a 
tuned push-pull circuit 23 . It was designed 
to run AC-DC style on the 1 20 volt power 
line. At 27 watts output, it runs at 45 
percent efficiency. 

Actually, my design was quite conserva- 
tive. A pair of VN0660N5s could handle 
substantially more power. They are de- 
signed to dissipate 45 watts each at 25°C 
The rated DC drain currenl is three-quar- 
ters of an amp. Another advantage is their 
price. At about $2.25 each, you could af- 
ford to use multiple transistors for high 
power. 

Considering the leneth of time that tran- 
sistors have been around, it is sad that 
progress in the RF power field has been so 
slow. Perhaps it is time for hams to take 
the lead again. So get out your calculator 
and soldering iron and go to work! 

References: 

1, VieelandL R.W, W6YBT, 'IMotes on a 
Lightweight Portable CW Transmitter with a 
Transformerless Power Supply," QEX* June 
l9K8,pp. 11-13. 

2, Vreeland, R.W., W6YBT, "More Gad- 
gets for your MFJ-9Q20/' 73, October 1 993, 
pp. 10-12. 

3, Vreeland R.W., W6YBT Trans- 
formerless Amplifier^ 73, August 1995. p| 

48-54. 



Number 71 on your Feedback card 



Antenna? What Antenna? 



A stealth antenna farm for a small lot. 



J, Frank Brumbaugh KB4ZQC 

RO, Box 30, c/o Defendini 

Salinas PR 00751-0030 



Is an efficient antenna farm possible 
on a small lot? Yes, if you are willing 
to confine your operation to the 
seven ham bands from 40 through 10 
meters, and are also willing to tweak an 
antenna tuner, which may be automatic 
or manually operated. With the new sun- 
spot cycle just now beginning, these are 
the bands where the DX will be, where it 
will be easier to earn WAS, and where 
there will be many opportunities for 
casual rag-chewing. 

But is it really a stealth installation 
that the neighbors won't notice? And 
how aboul restrictions against even TV 
antennas? How can this be possible? 

Yes, it can be made "invisible" to 
neighbors, inspectors and casual pass- 
ersby, even though it's right in view all 
the time. First I'll show you how to build 
it, then 1*11 show you some ways to com- 
pletely fool anyone looking for an an- 
tenna. In fact, even another ham who did 
not read this article would never guess 
you had an efficient antenna farm while 
he was looking right at it. Now, that is 
about as stealthy as you can get — and 
still work the whole world. 

The antenna farm 

The antenna farm described here re- 
quires only three dipoles to cover all 
seven ham bands efficiently. All arc 
slightly shorter than full-sized dipoles, 
but there arc no traps — nothing fancy, 
just wire dipoles. They can be installed 
and fed separately, although this could 
take them out of the stealth category. 
They can also be installed horizontally 
and fed in parallel with a single feedline. 
I don't recommend either of these op- 
tions; it is difficult to hide antennas 



which look like antennas even to a 
non- technical person. 

I recommend installing the three di- 
poles as inverted vees using a common 
high support at the apex, which can be a 
mast, pole, tree, or anything else which 
is high enough. Also, I recommend 
feeding all three dipoles in parallel 
with a single feedline. Best of all, the 

iC ¥our stealth installation can be 
made 'invisible' to neighbors, 

inspectors and casual 

passersby, even though it is 

right in view all the time" 

recommended dipolc lengths are all 
somewhat shorter than full half-waves 
and, while not resonant in any band, are 
easily and efficiently matched with any 
antenna tuner because all dipoles are 
close to the adjacent bands they are 
designed to cover. 

What you will need 

115 feet of antenna wire is sufficient 
to make all three dipoles, with plenty of 



wire left to make connections to the in- 
sulators. The center frequency of each 
dipole was carefully chosen so it will 
cover two or three adjacent bands, as 
listed in Table 1. 

Feeders 

I strongly recommend using 300- or 
450-ohm open-wire feedline instead of 
coax. Because these dipoles are not reso- 
nant in any ham band covered there will 
be varying amounts of reactance at the 
center of each dipole. Feeding a reactive 
load will cause standing waves on the 
feedline, and power will be reflected. 

This reflected power is subject to the 
same line losses as the forward power. 
Once it reflects back to the transmitter it 
is again reflected up the line to the an- 
tenna, where most of it is radiated and a 
small portion is reflected back once 
again to the transmitter If coax feeders 
were used the I-R losses would be much 
greater, and more power would be con- 
sumed in the coax on this back-and-forth 
trip. This situation occurs even with a 
1 : 1 match at the antenna tuner, since the 
tuner is only tuning the rig to the line, 
not the line to the antenna itself. In other 



Bands Covered 



40 - 30 m 



20- 17-15 m 
12 - 10 m 



Dipole 
Overall Length 

54 ft, 6 in. 

26 ft. 4 in. 

1 7 ft. 6 in. 



Length, 
Each Half 

27 ft. 3 in. 

13 ft. 2 in. 

8 ft. 9 in. 



Table 1. Center frequency of each dipole was carefully chosen so it will cover two or three 
adjacent hands. 

73 Amateur Radio Today ■ February 1 997 71 



words, standing waves will occur on the 
line regardless of what type of antenna 
tuner is used* 

Although similar standing waves 
and reflected power will occur on open 
wire feeders, the line loss is much less 
as the PR losses are so low as to be al- 
most inconsequential- Remember that 
reflected power is always returned 
back to the antenna, minus PR losses^ 
and re-radiated, minus the power re- 
flected due to the line/antenna mis- 
match. This means that reflected 
power is not "lost" power — it is only 
lost when using a high loss feedline 
like coax, rather than the low loss 
ladder line. 

Installation 

Because every ham knows how 
to erect a dipole, either horizontally 
or as an inverted vee, and will do so 
if separately installed and fed dipoles 
aie desired, I will describe only an 



Insulator 
Six Places 




Center 

Insulator 



Sokter 



A 



Fig. I. Bird's-eye view of the triple-dipole 

antenna installation* 



20-17-15 



Solder three dipole 

tegs and feeaec 

wire together 

on each side 



Fig* 2. Center insulator detail. 



easily-hidden 
installation with 
all dipoles erected 
as inverted vees 
and all using 
the same single 
support and fed 
in parallel with 
open-wire feed- 
ers. See Fig. l t 
which shows the 
completed instal- 
lation as view- 
ed from directly 
above the central 
support. 

Seven insula- 
tors will be re- 
quired: one at 
the common 

feed point, and one at each end of the 
three dipoles. Black braided 
Dacron® line about 3/16" in diam- 
eter should be used between each 
end insulator and its support point. 
The supports can be stakes driven 
into the ground, a hook on the side 
of a house or garage, a fence post, a 
tree — whatever is handy. 

Although the 60° spacing shown in 
the bird's-eye view of the antenna in- 
stallation is ideal, it is not a law of 
physics. Just space the halves of the 
antennas the best you can in the space 
available. The 60° spacing provides 
the least possible interaction between 
the dipole in use and the remaining 
two. 

As the ends of the antennas are 
brought downward to tie off the ends 
to form inverted vees, do your best to 



Insulator 



40-30 




2007-15 



40-30 



Ladder line 
Feeders 



have an included angle at the apex of 
each dipole of between 90° and 110°, 
Again, if space requires a somewhat 
greater or lesser apex angle, do the 
best you can. 

Be certain the ends of the antenna 
wires are not less than six feet, and 
preferably somewhat higher, above 
ground. This keeps anyone from com- 
ing in contact with RF on the ends of 
the antenna. 

Make sure the halves of each half- 
dipole are connected together at the 
feed-point insulator (see Fig. 2), 

Tuning up 

Your antenna tuner may or may not 
include a 4:1 unbalanced-to-balanced 
balun to match the unbalanced tuner 
output to the balanced feeders. If it 
does not, and all or most automatic 




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72 73 Amateur Radio Today • February 1997 



Rduehtisers* Indeh 



R-S.# page 


FLS*# 


351 


Absolute Value Systems ., 


. 13 


180 i 


68 


Advanced Battery Systems . 


.78 


99 


• 


All Electronics 




10 




Corporation 


?1 


276 


* 


AlphaLai> Inc 


35 


268 


57 


Antennas West 


... 1 




116 


Antennas West 


. 15 


* 


132 


Antennas West* 


. P3 


114 


332 


Antennas West 


.25 


• 


5 


Antennas West ,♦ 


.31 


142 


324 


Antennas West 


.39 


75 


336 


Antennas West 


.39 


227 


135 


Antennas West 


.77 


j 


380 


Antennas West 


.79 


193 


16 


Astron Corporation 


? 


• \ 


41 


Barry Electronics Corp 


. 13 


J 


42 


Bilal Company 


35 


• 


355 


Biological Hamming 


.13 


175 


168 


Buckmaste r Pub I i sh i ng . . . . 


. 15 


* 


56 


Buckmaste r Pub I i sh i ng 


p 16 


174 


224 


Buighardt Amateur 




• 




Center 


.77 


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v & & oaies* Jnc ■«.»*.,■»«■*■■ 


,19 


77 



page 

Coaxial Dynamics „.. 15 

Communication Concepts 39 
Communications Special tats , 19 
Computer Aided Technology . 81 
Computer Automation 

Technology *.„„,.,.,.„..... 83 

Cubex . 16 

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73 Amateur Radio Today * February 1997 73 



> 



Unbalanced Input 
from Tuner 



S77 




^ To 
Balanced 
Feeders 



Fig* 3. Unbalanced-to-balanced 1:1 balun. 

antenna tuners do not, you should 
build a balun to feed your antenna 
farm. Because the resistive component 
of the feed-point impedance on all 
bands is not too high, I suggest build- 
ing an unbalanced-to-balanced 1:1 
balun. 

Caution: Be sure to use a core large 
enough for the level of RF power your 
transmitter produces . This is extremely 
important! 

Fig, 3 illustrates the winding of a 
recommended 1:1 balun. It is bifilar- 
wound with enamel-covered copper 
wire of a size appropriate to your 
power output. For high power it is a 



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74 73 Amateur Radio Today * February 1997 



Turns = 10 



,m// 



AL 



Another source of a complete line of 
toroids is Palomar Engineers, Box 455, 
EsconditoCA92025. 

Hiding in plain sight 

Depending upon many things, includ- 
ing the sensibilities of nearby neighbors 
and/or homeowners' association restric- 
tions, you may find it necessary to cam- 
ouflage your antenna farm without 
compromising the efficiency of its radia- 
tion. One of the best ways to camouflage 
the mast or pole supporting the feed 
point of your antennas is simply to place 
a birdhouse on top. Thus, your antenna 
mount has disappeared, while remaining 
in full view* 

The antenna wires themselves escape 
notice, masquerading as guys stabilizing 
your lofty birdhouse. The end insulators, 
if they are white porcelain or glass, can 
be sprayed with black enamel When the 
enamel is dry, rub a thin coat of silicone 
grease over the outer surface of each in- 
sulator to preclude any bridging of the 
insulators by rain. Dow Corning DC -3 
or DC-4, or any product labeled "heat- 
sink compound" which does not contain 
white zinc oxide, are all good silicone 
greases. 

Now that only you can see your antenna 
farm, the problem of bringing open-wire 
feeders from just below your birdhouse to 
the shack is more difficult. You might get 
away with explaining that the ladder line is 
actually a ladder for the use of birds with 
crippled wings. Don't take the easy way 
out, it won't be that difficult. 



Parts List 

115 feet of antenna wire 

1 center insulator (feedpoint) 

6 end insulators 

Black braided Dacron® rope, 3/16" 

diameter 
1 unbalanced to balanced 1:1 balun 

(see text) 



Bring the ladder line vertically down 
the birdhouse pole, stapling it occasion- 
ally through the insulation, or use hot 
glue. Paint the line the same color as the 
pole, at least as high as you can reach 
standing on a kitchen chair. Adults will 
never notice it, because few adults pay 
any attention to anything much above 
eye level. 

The ladder line now will probably 
have to be routed through a length of 
PVC pipe from the pole to the shack 
wall, but it's not a good idea to have 
your feeders close to the ground. The 
pipe should be more than head-height 
above the ground and be painted to 
match the general area, perhaps even 
mottled to break up its lines. 

The pipe containing the feeders, if 
supported by a few uprights which have 
vines planted around them, will turn this 
part of your feedline into a growing 
frame for grapes, flowering vines, pole 
beans etc. It might also be a good idea to 
temporarily wind some plastic vines 
around the uprights and feeder pipe as 
immediate camouflage. 

Plastic vines can also be wound through 
ladder line and the feeders taken directly 
from the pole into a second-floor shack, 
though this might invite comment. 

If you want to find out just how stealthy 
you have made your antenna farm, invite a 
ham who has not read this article to your 
home and "cry on his shoulder*' a bit about 
the antenna restrictions and not being able 
to put up a decent antenna and see what 
suggestions he has to offer. Take him into 
the yard and ask for ideas. He probably 
will suggest a vertical attached to the side 
of the birdhouse pole. Then take him into 
the shack, turn the rig on, and let him be 
amazed at what he can hear as you have a 
QSO or two. Then, just to be friendly, tell 
him who told you how to do it 

Because each stealth antenna farm will 
be different, use your imagination. I've of- 
fered a few hints here, but you'll probably 
have even better ideas, And maybe you'll 
write about 'em. ~ 



Number 75 on your Feedback card 



Hentenna Footnotes 



Using cm EZNEC model to build a sample. 



Thomas M, HartADIB 

54 Hermaine Ave. 

Dedham MA 02026 



I like antennas and antenna articles. 
Recently, I have discovered the joys 
ol" modeling antenna designs on the 
computer with the EZNEC program 
(available from Roy LewaUen W7EL, 
P.O. Box 6658, Beaverton OR 97007: 
phone 503-646-2885, FAX 503-671- 
9046, E-mail w7el@teleport.com), and 
only building samples if the results look 
promising. 

73 printed an interesting article by 
KA0DAQ in the April 1996 issue, titled 
'The Hentenna/" For the first time, I 
found a complete set of formulas in print 
that helped in the design work. 

In order to learn more about the 
Hentenna, I reviewed my own antenna 
references, ran a model on EZNEC, and 
built a sample for the FM broadcast 
band. 

Evolution of the Hentenna 

A book, now long out of print, Radio 
Amateur's VHF Manual (©1972, ARRU 
describes the "Skeleton" or "Slot" an- 
tenna based on designs by B. Sykes 
G2HCG. The illustration shows the pro- 
cess that changed two horizontal half- 
wave di poles into the final rectangular 
Hentenna design. The antenna was 
popular at the time of publication and a 
commercial model was marketed by 
J-Beams Lid. The antenna is character- 
ized as horizontally polarized, with ver- 
tical sections that act as wide-spaced 
transmission lines. 

Etymology of "Hentenna" 

"Hen" comes from the Japanese word 
for "interesting" or "unusual." In an ar- 
ticle titled * Let's Make the 'Hentenna'" 
(QST, February 1982), Koji Sugihara 







Hentenna Computations 






MHz 


1/2 WL 


1/6 WL 


Total Wire 


Feed Point 


146.0 


3.4 


1.1 


11.5 


0.8 


Feet 




41.3 


13.8 


137.7 


9.6 


Inches 


90.9 


5.5 


1.8 


18.4 


1.3 


Feet 




66.3 


22.1 


221.1 


15.5 


Inches 


50.1 


10.0 


O-O 


33.4 


2.3 


Feet 




120.4 


40.1 


401.2 


28.1 


Inches 


29.5 


17.0 


5,7 


56.8 


4.0 


Feet 




204.4 


68.1 


681.4 


47.8 


Inches 


28.4 


17.7 


5.9 


59.0 


4.1 


Feet 




212.3 


70.8 


707.7 


49.6 


Inches 


21.3 


23.6 


7.9 


78.6 


5.5 


Feet 




283.1 


94.4 


943.7 


66.1 


Inches 


14.2 


35.4 


11.8 


118.0 


8.3 


Feet 




424.6 


141.5 


1,415.5 


99.2 


Inches 


7.2 


69.8 


23.3 


232.6 


16.3 


Feet 




837.5 


279.2 


2,791 .7 


195.7 


Inches 


3.6 


139.6 


46.5 


465.3 


32.6 


Feet 




1,675.0 


558.3 


5,583.3 


391.4 


Inches 


1.8 


276.1 


92.0 


920.3 


64.5 


Feet 




3,313.2 


1,104.4 


1 1 ,044.0 


774.1 


Inches 



JJ1UMS stated that the design was very 
popular on 6 meters (about 10% of the 
installed base). Horizontally polarized, 
the antenna was very forgiving about di- 
mensions; a 5-10% variance from de- 
sign specifications had little effect. The 
antenna could be fed with either 50 or 
72 ohm coax, directly or with a balun. 
The feed point was a Y-shaped wire that 



was moved up and down to determine 
best match before final attachment, 

Dimensions 

Table 1 shows Lhe lengths of the sides, 
as well as feed point location, based on 
the experiments by KA0DAQ. Clearly, 
the antenna is best suited to 10 meters 
and above. It would be possible to try 
73 Amateur Radio Today • February 1 997 75 



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CIRCLE 350 ON READER SERVICE CARD 

76 73 Amateur Radio Today * February 1 997 




Fig. |« Currents on the antenna during 

operation . 

one on 15 and 20 meters, but the 
structure starts growing large here, 
Hentennas on 40 through 160 meters are 
well out of the ordinary person's reach, I 
had no problem constructing and using a 
sample on 90.9 MHz, the local National 
Public Radio Station, WBUR in Boston, 
It works! 

The 10 meter report 

Bill Orr W6SAI included an illustra- 
tion and discussion of the Hentenna in 
his monthly column in Ham Radio 
magazine, May 1989. He discussed a 
letter from JE1DEN which contained in- 
formation on using the design on the 10 
meter band in Japan. 



a 2 


r 

f 






5 


~"N^— -v^x 


Y.S^Z^ 






b Org 






^^*^^^^fc TflJpL ^r *» jl J 








/jj Jo cleg 



Fig, 2. EZNEC elevation plot, perpendicular 
to antenna plane, 




X 



x 




Odeg 



Fig. 3. EZNEC elevation plot in the plane of 
the Hentenna. 

EZNEC report 

Fig. 1 shows the currents on the an- 
tenna during operation. Next, elevation 
plots were prepared to show that the 



"The Hentenna is a very 

interesting, often overlooked, 

design that can be used on HF 

and VHF installations" 

strongest radiation is perpendicular to 
the plane of the antenna. The takeoff 

angle is 1 1 degrees in the sample, favor- 
ing distance work. The elevation pattern 
in the plane of the antenna is, as ex- 
pected, attenuated and provides a high 
takeoff angle of 8 1 degrees. 

Switching to the azimuth plot, we find 
a very pronounced figure-eight pattern. 
This has been reported in the literature 
and supports the elevation plot data. The 
Hentenna is strongly directional and can 
be used with parasitic elements. 

Polarity considerations 

The Hentenna is horizontally polar- 
ized. Does this matter? The answer is 
"maybe/' If you operate on the HF bands 
and depend on the ionosphere, the an- 
swer is probably an unqualified "no." 
Refer to the ARRL Antenna Book 
(©1994, ARRL). Here, we find that in 
the range from 3 to 30 MHz, skywave 

transmissions change their polarizations. 



Antennas at either end of the connec- 
tion don't need to have the same polar- 
ization. 

For short-path communications, 
VHF FM work for example, polariza- 
tion may be quite important. Cross po- 
larization can result in 20 dB losses in 
cases where different methods are in 
use at the transmitter and receiver. 

Conclusions 

The Hentenna is a very interesting, 
often overlooked, design that can be 
used on HF and VHF installations. The 
literature contains references to instal- 
lations on 10, 6 and 2 meters. The 
structure is simple and rugged when 
properly assembled. The horizontal 
polarization may be a concern in VHF 
use, especially on repeater work. This 
design is one that should not be over- 
looked when planning additions to the 
antenna farm, or in my case, antenna 
garden (I have too little space to build 
a farm!). 




Fig. 4. EZNEC 

Hentenna. 



azimuth plot of the 



Neuer sry die 

Continued from page 69 

shots and she showed an immediate and dra- 
matic improvement. 

Though the medical literature has thou- 
sands of similar stories and doctors are quite 
familiar with this response, which they call 
the placebo effect, what they haven't done is 
find out how and why it works so they can 
ihen harness its power to help cure people. 

I've seen medical reports saying that the 
placebo effect can work in up to 80% of all 
illnesses. But no matter the percentage, here 
is a way which could help cure a wide range 
of illnesses that the medical industry is re- 
fusing to research and develop. Why? 
Simple, there isn't any money in selling 
placebo based cures. 

Back when I was a professional psycho- 
therapist 1 found that every illness had a psy- 
chological trigger. By de-acttvating this trig- 
ger the illness would go away. And the de- 
activating procedure was fairly simple. At 
the time the medical industry ridiculed the 
whole idea. In the intervening years doctors 
have come to admit the importance of psy- 
chological components in illnesses, but I 
defy you to find one doctor anywhere in the 
world who is making use of this knowledge. 

Twenty years ago I suggested in an edito- 
rial that one excellent application for per- 
sonal computers would be to use them in 
doctors* offices and hospitals to uncover the 
psychological trigger for illnesses, The proce- 
dure is so simple that even a desktop computer, 
operated by the patient, could be programmed 
to find these triggers for doctors. There would, 
I suspect, be a pretty good market for such a 
computerized diagnosis system. 



Then I'd have to write a handbook for 
doctors on how to de-activate the psycho- 
logical triggers, since I suspect I'm one of 
the few people left who know how to do this. 

What is l^uth? 

If I say that I believe that extraterrestrials 
are and have been among us for thousands of 
years, is your reaction that poor old Wayne is 
off his rocker? Or do you agree? And if you 
think I'm off my rocker, are you at least will- 
ing to look at the evidence that convinced 
me? 

Okay, how about telepathy, auras, spoon- 
bending, psychokinesis? These, too, are sub- 
jects that are off-limits for scientific investi- 
gation. Not only won't they be funded, ridi- 
cule and humiliation await the brave and in- 
quiring. 

Now let me be specific. Let's take Uri 
Geller, for instance. Was he just a stage ma- 
gician or was he really a psychic? Unless 
you've done some serious research you 
probably don't know that Geller performed 
for scientists under the most carefully con- 
trolled laboratory conditions* He has been 
videotaped while being carefully watched by 
both professional conjurers and scientists, 
using no materials provided by him or that 
he even had prior access to, remotely affect- 
ing scientific instruments, even producing 
objects out of thin air, and locating hidden 
objects with no errors. 

Getter submitted to endless exhaustively 
controlled experiments at several colleges, 
For instance, a dozen aluminum film cans 
would be put on a table. Some had water in 

Continued on page 78 



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73 Amateur Radio Today * February 1997 77 



NEUER 50 V DIE 
Continued from page 77 

them* some steel balls, and some sugar 
cubes. Gelter did not touch the cans, but was 
able to identify the contents in all 12 cor- 
rectly. The odds were over a million to one. 
Geller was able to make Geiger counters 
click, and other scientific instruments give 
weird readings. 

Yes. I agree, Tra off my rocker. But that's 
because 1 haven't time to sit around rocking 
when 1 prefer rocking the boat I've a nice 
rocker — a gift from an appreciative college 
president for my consulting work for him 
and the deans. But how can I spend time sit- 
ting around rocking in my old age when I 
feel I should be writing about the anomalies 
that the scientific establishment is not just 
ignoring, but is actively trying to prevent 
being investigated? 

Like, did you know that plants somehow 
communicate via UV? The research results 
are amazing, but the odds are that you've 
never seen them published. Ditto the work of 
Rife, Naessens, Reich, Ott T Baekster, Tesla, 
Rawlcs & Davis, and a bunch of other 
martyred scientific pioneers. Books about 
many of *cm are on my $5 list of books 
you're crazy if you don't read. On trips, my 
suitcases are more loaded down with books 
I'm reading than clothes. Or are you like the 
average American schoolteacher, who reads 



one book a year (usually fiction)? 1 read two 
or three non-fiction books a week. Sure, 
some are a waste of time, despite high rec- 
ommendations from readers, but others go 
from good to superb, with a few making it 
when I update my book list. 

Perhaps you can understand why I see 
so many pioneering opportunities for anyone 
with the guts to oppose the scientific 
mainstream. 

DayCare 

The election of state senator Jeanne 
Shaheen to governor of New Hampshire 
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on the Educational Subcommittee of the 
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well. 

Jeanne had a fixation on the need for New 
Hampshire schools to be legislatively forced 
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agree that youngsters should be given every 
opportunity to learn during their early years, 
but I'm just not a fan of having Ehe govern- 
ment force everyone to do what a legislature 
has decided is best. 

For that matter, I am most critical of the 
whole "day care" concept. I gram that there 
may be some day care centers that provide 
children with the opportunities to learn a 
wide variety of things. However, I suspect 



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that most of them operate like the ones I've 
seen where the children are started early be- 
ing taught regimentation, and their exposure 
to new ideas and experiences are limited to 
what Sesame Street and Mr Rogers provide. 

Here is a time, when kids are two to five 
years old, when around 90% or so of their 
lifetime character is being formed. This is a 
time when they should be provided with the 
tools and encouragement to leant and 
experiment. 

This is the best time to teach children sev- 
eral languages. This is when they should be 
helped to experiment with drawing, clay, 
painting, playing musical instruments, ex- 
ploring nature, and be taught any skills that 
may interest them — like juggling, gymnas- 
tics, playing games, learning to read, build- 
ing their vocabularies, skating, skiing, swim- 
ming, and so on. This is the time when indi- 
vidual interests should be encouraged rather 
than group conformity. Between genes and 
early nurture, everyone is different. But it 
takes a teacher/salesman to enhance the 
positives and bring out the uniqueness of 
each child without stifling their curiosity and 
enthusiasm. 

Early animal trainers used punishment as 
their main method of teaching. Then it was 
found that far faster and better results were 
obtained using kindness and reason. This 
concept has not yet caught on with many 
teachers and parents. It does require that 
the teacher be able to outthink the animal 
(or child) and devise a way to convince the 
animal that it wants to do what the teacher 
is encouraging. This results in a happy, 
cooperative animal. And child. 

Perhaps if we change the name of day care 
centers to early learning centers that would 
help. Ditto children's garden, a.k,a. kinder- 
garten, which should merely be an extension 
of the early educational and development 
process. Given the opportunity, encourage- 
ment and the tools, many kids will be able to 
enter the first grade already accomplished in 
reading, writing, dancing, acrobatics, play- 
ing one or more instruments, able to speak 
several languages accent- free, be good 
swimmers, and have already developed sev- 
eral other skills. To do other than this is, to 
some degree, putting children in straightjac- 
kets menially and developmentally. And re- 
member, that once the window of opportu- 
nity for children to learn certain skills has 
passed, it is a lost opportunity. For instance, 
never again will children be able to learn 
many languages as easily. 1 suspect that 
musical and dancing skills are the same. 

Portable Classrooms 

I've proposed that state school systems 
encourage (and fund) their schools to build 
portable laboratories into trailers so the facil- 
ity can be shared by a number of schools. 
This would make it so that chemistry, wood- 
working, metalworking, electronics, com- 
puter, photography, video production, audio 
recording, music appreciation, cooking, and 
other such expensive equipment systems 
could be shared by several schools, thus 



78 73 Amateur Radio Today ■ February 1997 



providing a greater learning experience at a 
lower cost per student, 

1*11 bet a good deal of corporate funding 
could be made available to help build these 
mobile labs. 

For the younger kids this would make a 
way to bring exploratoriums to them, to pro- 
vide them access to more expensive musical 
instruments such as pianos, electronic 
instruments, and recording facilities, 

But how can we bring about the needed 
change? If you do nothing, nothing will 
change. If you start pushing for change most 
people will fight and ridicule you. 

Are you a leader or a follower? Our 
present day care and school system incul- 
cates us early on to be followers. Don't rock 
the boat. The nail that sticks out gets ham- 
mered down. If it ain't broke, don't fix it. Ya- 
ta-ta, ya-ta-ta. Maybe, if you'll help fix our 
educational system, we'll have more leaders 
and fewer followers. Boy, will that screw 
things up! Ha! 

Arrested! 

Greg Godsey KF4BDY, a 16-year-old 
ham from Paulette Court, Kentucky, was ar- 
rested while demonstrating the severe 
weather Skywarn system to a group of 
people, He was charged with the possession 
of a police scanner, impersonating a public 
servant and disorderly conduct. The police 
confiscated his Radio Shack HTX-202 2m 
HX 

The HT was later returned when the police 
found that it was a legitimate piece of ham 
radio equipment which could not be used to 
eavesdrop on their communications. But for 
some reason they'd taken it apart, so it had to 
be sent back to Radio Shack to be serviced. 

And what about the impersonating a pub- 
lic servant deal? Well, Greg had an Amateur 
Radio Emergency Service ID. But the police 
and the court refused to accept that ID, so as 
far as they are concerned a credentialed 
Amateur Radio Service volunteer is imper- 
sonating a public servant and that constitutes 
an act of disorderly conduct. 

Thanks Chicago FM Club Squelch Tale 
for that gem, Remember, the police are your 
friends and judges are ex-lawyers. However, 
if you have an ARES card, it can get you ar- 
rested. You go to jail and the court collects 
the $200. 

Nondisclosure Agreement 

How'd you like to make a few million 
bucks? Well, I have an idea for a simple elec- 
tronic product that'll be easy to make and 
should sell by the carloads. It could almost 
revolutionize an industry. We need a manufac- 
turer and a hundred or so sales and service reps. 

Now, before I disclose the details of my 
idea I want it understood that the reading 

of this constitutes a legal binding contract 
between you and Wayne Green that you 
will (a) not disclose this idea to anyone 
else, and (b) if you decide to get involved 
in the manufacture or marketing of the 
products described that you will reserve a 



minimum of 2% of gross sales as a royalty 
for said Wayne Green. 

That out of the way, here's the sneaky 
plan. The germ for this idea was spawned 
back around 1978 when Sherry and I had 
lunch with Ed Juge W5TOO at a Mexican 
restaurant in Ft, Worth, 

Fd known Ed for many years. He'd ad- 
vertised his Juge Electronics store in my 
magazine and we'd gotten to be friends. 
Cut to 1975 when I was taking the first is- 
sue of my brand-new Byte magazine 
around to drum up advertising. My first 
stop was with Sphere Computers in Salt 
Lake City. Then down to Albuquerque to 
visit Ed Roberts at MITS. From there I 
stopped at Ft. Worth and dropped off some 
copies of the magazine with Ed Juge, ex- 
plaining that I felt that the personal com- 
puter field was going to eventually be a 
huge new business that would eventually 
be larger than the automobile industry. 

Ed bought an Altair 8800 from MITS 
(the first microcomputer) and was hooked. 
The ARRL*s so-called "incentive licens- 
ing" proposal had so gutted the ham busi- 
ness that Ed was fed up and was looking 
for something new to do. It was at this 
time that Radio Shack decided to get into 
the personal computer business. That's a 
whole story in itself — one that needs to be 
told. Anyway, since Ed was right there in 
Ft. Worth, and already had some experi- 
ence with microcomputers, he joined Ra- 
dio Shack to help them market their TRS- 
80 computer. It was a great little computer 
and, with the help of several thousand 
stores to sell it, it quickly grabbed the 
lion's share of the market. 

Getting back to that Mexican lunch. 
This restaurant had a little flag on each 
table for us to raise when we were ready 
for more hot sopaipillas. Great idea. (Then 
there was a restaurant in Manchester (NH) 
that had a light you could switch on to call 
the waiter. Also a good idea.) 

You have the same problems I have. You 
have to wait for a menu. Then you have to 
wait for the waiter to notice you're ready 
to order. When you run short of water or 
something, getting the attention of the 
waiter is difficult. The worst is getting the 
check. At that time the waiter totally dis- 
appears as your frustration mounts. It 
helps you understand why these people are 
called waiters. They make you wait. And 
wait. It's no wonder fast food has gotten so 
popular. 

Okay, Gadgeteers 

What we need is a beeper system, with 
one unit attached to your waiter to show 
the number of the table wanting service, 
and a unit on your table to call the waiter. 
Whether it is infra-red or microwave is up 
to you. It wants to be simple, as inexpensive 
as possible, legal, fairly foolproof, and not re- 
quire much service. If there is such a product I 
haven't seen it at any electronic shows, nor 
have I heard of any restaurants using one. 

Continued on page 81 



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73 Amateur Radio Today * February 1 997 79 



Number 80 on your Feedback card 



The Quest for the Ideal QTH 



A New Jersey paradise for this ham. 



Bert Simon K2FZ 

21 1 NW 45th Avenue 

Coconut Creek FL 33066 



At one time my goal was to be the 
"buzzard on the highest perch." 
I sought i he ideal radio loca- 
tion — and eventually found it, lived on 
it, and enjoyed every moment of being 
there* 

I laid claim to having the highest per- 
manent resident ham location in New 
Jersey. The highest point in New Jersey 
is at an area called High Point, and if my 
memorv serves me rieht it was in excess 
of 1 ,800 feet above sea level The loca- 
tion 1 eventually sell led for was at 1,240 
Teel above sea level and was approxi- 
mately 300 feel above average terrain. A 
60- fool tower would put my beam anten- 
nas more than 1 300 feel above sea level. 
Although I worked olher stations in New 
Jersey thai were higher, they were Field 
Day setups — with High Point, of course, 
being one of the favorites. 

It doesn't lake a rocket scientist to re- 
alize that when it comes to strong 
ground wave signals, the higher the 
ground and the clearer the shot means 
the stronger the signal And so the search 
went on to find that elusive higher 
ground which would lead to a ham 
paradise, the ideal radio location. 

There were olher factors to consider. 
Was the QTH readily accessible without 
investing thousands of dollars to build a 
road? Was electrical power available or 
would I be required to spend additional 
kilo bucks to put in power lines and/or an 
independent generator? Could I get in 
and out when the snowstorms arrived? 
Was it far enough away from the very 
high voltage power lines which could ra- 
diate enough 60-cycle harmonics to 
bounce signals olT Saturn? Were there 
any restrictions (or possibility of) 

80 73 Amateur Radio Today * February 1997 



involving townships or neighbors who 
might not appreciate the wonderments 
of an antenna farm? At one time I was 
approached by some township officials 
who voiced the opinion that 4 They 
weren't sure whether they wanted radio 
towers in their township." I informed 
them that I had permission from the FCC 
and the FAA to construct the lowers and 
that was all I needed, but that was then 
and this is now. I would recommend fur- 
ther study and perhaps some legal ad~ 
vice. The other factor, carrying perhaps 



"The band was dead with 

respect to skip, but on many 

occasions ZSs would break in 

just to let me know that I was 

the only stateside station being 

heard" 



the mosi significance, was the ability to 
convince a spouse that "this is the place 
to live." 

Choosing the site 

I started on my ham crusade by ob- 
taining geodetic and survey maps for the 
entire state, and then spent a great deal 
of time studying them and visiting many 
proposed locations. Was the subject 
QTH far enough from heavily traveled 
highways so as not to be subject to auto- 
mobile ignition noise? Finding proposed 
locations was relatively easy but finding 
the ones that had land available and ac- 
cessible was another problem 1 recall 
many disappointments. 



I made my choice and Fm happy lo re- 
port that between 1959 and 1978 I had 
the greatest ham location Thai one could 
ask for — and one every ham should ex- 
perience. There were certainly many 
higher locations available throughout 
the United States but were they within 
radio metropolitan range of an area such 
as New York City? Mine was, and that 
added so much joy to the ground-wave 
contacts, which had an approximate ra- 
dius of 200 airline miles. The QTH I had 
chosen was about 40 miles northwest of 
Central Park, New York City; Tor those fa- 
miliar with New Jersey, it was in Jefferson 
Township at the intersection of Moms, 
Passaic and Sussex counties. It was on the 
northwest ridge bordering the Oak Ridge 
Reservoir, which supplied water to the city 
of Newark. My five acres of property bor- 
dered on thousands of acres belonging to 
the City of Newark Watershed. 

There were no restrictions on anten- 
nas. I could put up anything I wanted. I 
settled on a seven-element triband beam 
for 20 through 10 meters and antennas 
ranging from 1 1 elements on 6 to 20 ele- 
ments on 2, not to mention full-size di* 
poles on 80 and 40 meters. Life was 
good! 

Another desirable factor in a great 
QTH was lo have a low-noise location, 
radio-vuse. This was borne out bv the 
constant "whisilens" (part of an iono- 
sphere phenomenon) I would detect in 
the 20 to 30 MHz range. I would pick 
them up slightly higher than 30 MHz 
and observe on a panalyzer as they 
waddled down in frequency (it reatly 
looked like waddling) until thev dimin- 
ished somewhere about 20 MHz after 
sort of TMing 7 ' themselves to death, 



Some highlights 

I can recall one winter snowstorm 
when all travel came to a halt. I heard 
some QRN on the 15 meter band thai 
sounded like noise being generated from 
some type of an electrical appliance. I 
left the door of the radio shack open, 



caused that interference; the signals 
weren't that strong and besides, I 
couldn't find anyone else who could 
hear it to confirm its presence. 

I remember, with delight, many 
evening ground-wave QSOs with New 
York City/Long Island hams which put 
my antenna in the direction of South 



'7 could put up anything I wanted— life was good! 



*y 



stepped out into the snowbound road 
and looked down into the valley where I 
could see a section of Route 23 in 
Stockholm, New Jersey, which was ap- 
proximately three miles away. I heard 
the noise in the receiver and simulta- 
neously spotted a puff of smoke coming 
from a snowplow. This was repeated 
several times until I realized that the 
snowplow was the source of the noise 
and since it was diesel-operated, what I 
was hearing was not ignition noise, it 
was alternator noise — three miles away. 
Early morning differences in noise back- 
ground could be detected depending 
upon the pointing of the antenna with re- 
spect to the sun. I can recall observing 
some weird noise which sounded like a 
mishmash of several signals when the 
antenna was pointed in a certain direc- 
tion, which happened to be towards the 
abandoned Edison mines, about eight 
miles away. I never did find out what 



Never shy die 

Continued from page 79 

Step one is to design the transmitting and 
receiving units, Keep 'em simple. Sure, Til 
be glad to publish your solution, if it looks 
promising. And yes, any manufacturers who 
decide to use it should pony up a 2% on 
gross sales royalty to you too. 

Once something like this starts to catch 
on, every restaurant will have to invest in a 

system. 

My preference would be to use infra- 
red — like your TV remote control units. 
With a little power a table unit can cover a 
large area, A booster can be insialled if 
needed to cover the kitchen* 



Letters 

Continued from page 62 

While waiting for one of their security people 
to drive me back to my apartment, the Co- 
lombian Navy captain and I were alone and 
he told me about an encounter one of their 
frigates had with a UFO one night while on 
patrol along the Colombian coast. Recently 1 



Africa. The band was dead with respect 
to skip, but on many occasions ZSs 
would break in just to let me know that I 
was the only stateside station being 
heard, 1 guess having a Henry 2K4 and 
six elements on 15 didn't hurt. On many 
occasions I would work 15 meter 
ground-wave stations at a distance of ap- 
proximately 200 miles and the ham on 
the other end would excuse himself so 
that he could work "other short skip 
stations/' 

So why did I give up this ham paradise? 
It was just time to do something else. I sold 
all my possessions, bought a sailboat and 
lived aboard while spending the next 15 
years in the sunny Caribbean between 
Puerto Rico and the Virgin Islands. 

Within the past year I had occasion to be 
within five miles of my old QTH and 
couldn't resist visiting. My old ham shack 
was now in use as a garage — to coin a 
cliche, you can't go home again. 



Hey, do Sherry and I get some free meals 
out of this? 

Selling Music 

For that matter, you should be able to 
make a nice living selling audio systems to 
restaurants, complete with CD players and a 
set of appropriate ethnic music CDs. Mexi- 
can music for Mexican restaurants; Italian, 
Chinese, and so on. The sales and service in 
providing good music for a few hundred res- 
taurants should keep you out of trouble. The 
next thing you know you'll be on your way 
to Mexico, portable digital recorder in hand 
Or Greece. Or Japan. Oh, and don't forget 
that 2% for Wayne, On gross sales, 



had a Colombian AF colonel in one of my 
classes at DLIELC, so I asked him if he had 
ever been given a briefing in which he was 
told that we have been having extraterrestrial 
visitors. Looking at me directly* he responded, 
"Yes," Most Colombian AF officers appar- 
ently have not had such a briefing, only those 
working at the highest levels. 

Continued on page 82 





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Letters 

Continued from page SI 

A couple of years ago I partici- 
pated in a MUFON investigation of 
a family's encounter with a UFO 
that had hovered over their farm- 
house near San Antonio, frighten- 
ing them badly. There were three 
witnesses: a mother and two of her 
children. The 13-year-old daughter 
stayed outside looking at the craft 
the longest and experienced some 
physical symptoms (sunburn, fever, 
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younger son will not go outside the 
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answers to the questions being 
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That's simple. Cliff: We believe 
what the government tells us. The 
government wouldn't lie to us, But 
then there are a few troublemakers 
like you and me. I personalty know 
the government is still lying about 
Amelia Earhart, even after 60 
years. 

A few years ago I was called by 
a farmer to look at some crop 
circles in Francestown, NH. I talked 
with the woman who lived next to 
the farm and she told about a UFO 
that had hovered over her house for 
several minutes a few nights previ- 
ously, scaring the heck out of her 
and her children. When her hus- 
band got back he ridiculed her and 
the kids. The next day he apologized 
when he reported that the staff at 
the Crotched Mountain Children's 
Rehabilitation Center a few miles 
away reported the same silent 
bright light hovering over their 
buildings that same evening f and 
then zooming away at an incred- 
ible clip, 

Then there's a chap with the 
highest security clearance who is 
a consultant to President Clinton 
who called me a few days ago. 
He *s had several contactee expe- 
riences himself and his son, in 
Annapolis, reports that they are 
teaching the upper class students 



82 73 Amateur Radio Today * February 1997 



that the ETs are already here. I 
do wish someone would teach 
these critters to talk instead of 
always using telepathy, and lend 
them some HTs so we could let 
them hear what a pile up sounds 
like.,. Wayne. 

John Peters K1ER/KH6. You 
asked for a report on Dayton. Well, 
in brief, it stank. The WX used to 
be wet and cold, which was easy to 
handle with a waterproof jacket. 
This year the stupidity of the shift 
to May was demonstrated by pour- 
ing rain for several days before the 
Ham Vention, making it possible for 
the humidity to be unbearable on 
Friday and Saturday when fhe tem- 
perature was unbearably hot. The 
flea market seemed to be about 50% 
full* with many of the spaces pur- 
chased by people looking for a 
close-in parking space. Nothing in 
the flea market space but a parked 
vehicle. The flea market was not 
taken over by computers, it was 
taken over by completely useless 
junk — old lab equipment (junked 
by hospitals), old telephone 
equipment junked by some tele- 
phone company. Much less ham 
gear or computers than before. 
The tent area, normally known for 
the two or three inches of water 
running over your feet, was hot 
and humid, and contained basi- 
cally the stuff that didn't sell at 
the local Radio Shack. The flea 
market was a bust. The inside dis- 
plays were the same gang as 
usual. It would be hard to tell one 
year from another, except that it 
was hot. 

You should have had your own 
forum in competition with those 
scheduled. Best example was the 
DX forum. Scheduled to start first 
thing in the morning with a set 
schedule of topics. So far so good. 
The first event was Bill K from the 
DXCC desk who was scheduled to 
talk for 30 minutes or so. He took 
five to say the card checking back- 
log is gone and all's well with the 
world. The DXAC chair then an- 
nounced that there was really noth- 
ing controversial going on with the 
DXAC (probably the most blatant 
statement before the presidential 
lies started) and sat down. With no 
questions or arguments, and since 
the forum was then approximately 
50 minutes ahead of schedule (the 
later speakers had not arrived), they 



just adjourned! The speakers ar- 
rived to find an empty hall. The 
DX Dinner was not improved 
over prior years. But anyone who 
doesn*t know that deserves bad 
food, bad acoustics and bad ser- 
vice. 1 was supposed to help open 
a hospitality suite 30 minutes be- 
fore the scheduled end of the DX 
banquet, and at that appointed 
time the banquet food had not yet 
been served. I could discuss other 
events, but why bother? The only 
reliable high spot was the bar on 
the top floor above the DX din- 
ner, which was as good as ever 
in spite of the hotel sale to the 
Holiday Inn chain and name 
change. Same friendly staff 
every year. 

They should move the event 
back to April when the weather can 
at least be compensated for with 
clothing. Don't ask why any sane 
person would go from Hawaii to 
Ohio in May ! I figured it was close 
enough to the International DX 
Convention in Visalia, so why not? 
Now I know why not. At least the 
museum at Wright Pat had a few 
new exhibits, and I saw a few hams 
I knew. I may go next year just for 
the Collins Collectors meeting and 
skip the rest. I figure Slick Willie 
is going to get us into a war in 
Korea again by continuing to 
weaken the military, and the troops 
will need phone patches home. I 
need more things for the MARS 
frequencies before it starts. 

I had expected to hear you at 
Dayton; sorry you weren't there. If 
you want to lose weight, the frxnl 
and heat will sweat off a few 
pounds, I'm not sure any magic is 
involved in living long. Just stay 
away from doctors and hospitals 
(that's where the pathogenic organ- 
isms are found!) and have DNA 
from great-great-grandma who 
lived to 104, grandparents to 98, 
and eat less. 

Hmm t by publishing your letter 
I've probably guaranteed that I 
won *t get invited to speak next year. 
C*est la vie. But, how about some 
positive tetters? Some of you must 
have had a reaily good time! Speak 
up. However, with that humidity 
and temperature I can understand 
why the speakers didn V want to talk 
very long, The thought of around 
50,000 pounds of ham fat in a 
closed steam room is challenging... 
Wayne. 



Number 83 on your Feedback card 

Updrtes 

Resistance is futile? 

If you look at Fig, 1 of "En- 
hanced Automatic Voltage Con- 
troller" on page 43 of the January 
issue you'll see that we neglected 
to label one of the resistors. The 
resistor right next to R12 is Rll. 

Frank-ly speaking... 

In Frank Brumbaugh's "Audio 
Filter Alignment Generator" from 
the December issue (page 42) 
there was a typo in Fig. I , The 3 
was accidentally labeled 9, 

In addition, Frank sent us a 
memo saying that there have been 
some problems with the 74LS90 
chips: If the output from pin 1 1 
of U2 does not divide by 5, you 
should take the output from pin 8 
instead. 



Bruce Muscolin© W6TOY/3. 

Dayton Bombed? I think not! 
Seemed to me the crowd was pretty 
much on a par with last year. True, 
nothing like five years ago, but still 
a fun and worthwhile trip, and no 
rain! 

One group of hams actually had 
a bumper year this year at Dayton — 
the QRPers. The story began in 
1 995. Traditionally, like many other 
special interest groups, the QRPers 
hold a separate meeting. Our meet- 
ing is sponsored by the QRP Ama- 
teur Radio Club International 
(QRP-ARCI) and is complete with 
a hospitality suite, vendors, radios 
to operate, and a place to sit and tell 
war stories to friends. QRP enthu- 
siasts from around the world attend 
each year, with a large group 
coming from the G-QRP club. 

QRP is thought by many to be 
the fastest grow ing segment of ama- 
teur radio today. Certainly there has 
been tremendous interest in low 
power operation as evidenced by 
regional and national club member- 
ships in the thousands and an ac- 
tive Internet list with nearly 2,000 
members. However, the "dumbing 
down" of ham radio over the last 
25 years has led to many hams who 
have less than a solid working 
knowledge of the technology 
underlying iheir hobby. 

Continued on page 85 



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The latest electronics compo- 
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84 73 Amateur Radio Today • February 1997 



Kepro Named Distributor 



Kepro Circuit Systems, Inc. T a 
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mercury- vapor lamps, pulsed-xe- 
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AM Radio Log 

The National Radio Club's 
17th Edition of their AA/ Ratlin 
Log is now available, lis 312 
pages list the US and Canadian 
AM broadcast stations by fre- 
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a cross reference by call letters 
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call, address, format, networks, 
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powers, antenna, time /one, and 
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other stations. Box 164, 
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Letters 

Continued from page 83 

Last year, Bob Gobrick W A6ERB/ 
VOIDR B and 1 sat in the QRP- ARC1 
hospitality suite and kicked around an 
idea we hoped would change this. 
Coming from engineering back- 
grounds, we both have extensive ex- 
perience with technical conferences 
and trade shows. And what else is 
Davton if not a trade show with a few 

pi 

technical conferences thrown in? We 
thought that a QRP technical confer- 
once would enhance everyone's en- 
joyment of the QRP activities, and 
perhaps even raise their level of 
technical knowledge. 

We envisioned some of QRPs 
"great u hite lieads" holding forth on 
topjcsol interest to all: w hai H s the tvst 
antenna, what* s the best band, how 
do radios really work, how do you 
build a radio, etc. We decided on the 
Thursday before the llamveiuion 
opens. We thought there might be 20 
or 25 of our fellow QR Pers w ho' d use 
up an extra day of vacation and spring 
for the extra expenses. Surprise, sur- 
prise — we had 105 enthusiastic 
QRPers in the audience. Dayton 
Bombed? Not at the Day *s Inn— Day* 
ton South! Yes, we're going to do it 
^ain next year, and you have my per- 
sonal invitation to attend five, on me! 

How can I pass up a free meal? 
Meanwhile. Bruce, the more 
articles I can publish on QRP, the 
bigger turnout you 11 have, so let '$ 
see articles on QRP rigs, reviews 
of kits, uful so on. What's the best 
bat kpac k an tenna ?.., Wt iyne . 



Evan Rolek K9SQG. Your 
"How About \I;aV editorial really 
got me going. Hams demand no- 
tune transceivers. They want auto- 
malic antenna tuners to match the 
Impedance of their linears, keyeis, 
voice synthesizers, automatic CW 
copiers, and motorized crank- up 
towers, so one might think that 
hams arc lazy. But for some un- 
known reason they have an obses- 
sion with PCs and shun Macs, 1 
heard a chap explaining proudly 
that it only look him two days to 
get his CD-ROM installed and 
working. With a Mac, even a nov- 
ice can get a CD-ROM working in 
less than 10 minutes. I used to joke 
with PC users because, unlike w ith 
the Mac. they could only use eight 
characters to name tiles, and no 
uppercase, commas, blank spaces, 
etc, Now. with Windows L J5 
they're saying, "Hey, you know; I 
can name my files now!" Just com- 
pare the number i^ help books an J 
help courses at local schools 
for PCs vs, Macs. Missed you at 
Dayton. 

Golly < Evan, you convinced 
me!,- Wayne* 

Don Black} s KWQN. 1 just got 
through reading your editorial 
called 'DebacleT' in the Septem- 
ber 7i. My response to your com- 
ments is that you are applying what 
happened to us as youngsters to a 
new time and place. That is diffi- 
cult to do. In your opening para- 
graphs you speak of that nasty 
group called "hams" who provide 
the least in the way of benefits to 
the public in return for their use of 
billions of dollars of spectrum. Re- 
ally? I started on the ham bands 
back in 1959 \\ ith a Novice license. 
Today 1 hold the amateur Extra, all 
four FCC Commercial licenses, a 
masters degree, and have the title 
Systems Design Architect and En- 
gineer, Motorola Land Mobile 
Products Group. 1 am designing 
some of the most sophisticated digi- 
tal encrypted land mobile products 
that will benefit an entire world of 
people. And those products encom- 
pass everything from better spec* 
trum utilization to the most 
"Unciackable" encryption methods 
to be used for customers like United 
Slates Secret Service. FBI, US 
Border Patrol and US military cus- 
tomers. And where did it all start 
and where does it continue? With 



my love for radio, which vias 
sparked by ham radio back in 1959. 
Our company has many hams 
working on hundreds of diverse 
projects to aid mankind now and in 
the future, and this includes using mi- 
croproccssor controls for everything 
from the cars we drive to the micro- 
wave ovens we cook in. Where did 
these engineers get their start? Ham 
radio. 

Yes, Wayne, it appears on the 
surface (to you) that amateur radio 
is becoming a waste. And if you 
look at Dayion on the surface, yes, 
there are some real lowlifes thai arc 
entering the hobby, but they are the 
same lowlifes that take up a slot in 
life, drink beer and don't give a hoot 
for their country and/or fellow man. 

You made a statement that al- 
luded to ham clubs not helping 
youngsters understand radio and 
electronics. Have you ever taught 
a class recently ? 1 have taught over 
400 people now everything from 
the Novice through Extra and the 
Commercial FCC exams. You 
know what everyone wants today? 
They want a license to either chat 
on the radio or get a joh they won't 
be able to handle. It has nothing to 
do with ham radio: it has to do with 
the fundamental idea that our gov- 
ernment in this country has encour- 
aged: That failure is OK, reading 
books is boring, and you get a joh 
just because you are a minority. The 
kick-ass, get-tough, dig-in-and- 
fight attitude is gone in the United 
States, Look at how simple the ham 
exams are today, I leach the no-code 
in four evenings and have had 75 
students so far score no less than a 
90 on any element they take, 
Where's the 1960 attitude or Two- 
thirds of you just flunked your Ex- 
tra theory ( 1 * questions, of which 
10 were draw-thc-schematicsT *? 
We have become a soft, give-away 
country, Wayne, Why not ham ra- 
dio? Give it away Lo a bunch of mo- 
rons whom the government can 
then control. Thaf s the bottom line. 

I go through this every day — see- 
ing newly graduated engineers who 
got straight A*s in engineering 
school not be able to tell me how 
RF energy gets from the transmit- 
ter to the antenna down a coaxial 
transmission line. They have no 
idea, yet when 1 check their records: 
An A in Fields class. Give the 
grades away so our colleges can 
remain in business. 

73 Amateur 



Straying away from ham radio for 
a minute, 1 am also a private pilot with 
an instniment rating. 1 have talked lo 
manv of mv ham buddies who flv as 
captains with major airlines. I have 
asked them point blank, "Is there a 
movement in the United States to get 
rid of private pilots in American air- 
space?* The answer has been a re- 
sounding 'Yes!" Might as well, 
Wayne; they lit your guideline of 
'least benefits to the public in return 
for their use of billions of dollars of 
spectrum (airspace) " 

Say what you want, Wayne, it's 
your magazine and your feelings. 
But don"! blame ham radio, ll has 
and will remain a vehicle for people 
to have fun with electronics and 
explore the field of RF communi- 
cations. Who knows who the next 
engineer we hire will be. He might 
be the kid we are looking for to de- 
velop a new encryption method 
because he has been reading in 
depth on digital coding methods — 
something lhai was a spin-off of 
high-speed packet radio operation. 
I hope you will lighten up, Wayne. 

Dtm. I*U lighten up when I see 
some articles coming in from you 
to help get the readers interested in 
pioneering ham digital voice com- 
munications. But my main message 
is that either we start cloning hams 
like you in quantity or we *re gon- 
ers. Sure, we have a few youngsters 
coming into the hobby and going 
for high-tech careers, hut it s about 
one-tenth as many us we used to 
provide the electronics industry. 
Meanwhile the industry has grown 
by a hundred times, and shows no 
sign of slowing down, Don, I read 
a thick stack of ham club newslet- 
ters every month and only a few 7 
show an}- signs of serums recruit- 
ment and giving tlteory classes. Our 
kids* to\% f grades and lack of moti- 
vation are a proline t of our govern- 
ment-controlled school system. If 
we can get the government the heck 
ouf of our schools fund a hunch of 
o the r s itnila r ex pet is i \ e fa i lures ) 
we 11 be a whole tot better off. Even- 
tually if there f s no quid, there isn't 
going to be any quo... Wayne. 

Don Law she NVY2S, In 
reference to obtaining adhesive- 
backed copper foil for antenna 
construction, any craft dealer worthy 
of the name handles this tape, gener- 
ally in the "stained glass" section. My 

Continued on page 86 
Radio Today ■ February 1997 85 



nan 



Brrter 



Number 86 on your Feedback card 



V Buy 



Turn your o*d ham and computer gear into cash now. Sure, you can wart tor a 
hamfest to try and dump it. but you know you'll get a far more realistic prtce if you 
have it out where 100.000 active ham potential buyers can see it than the few 
hundred local hams who come by a flea market table. Check your attic, garage, 
cellar and dose! shelves and get cash for your ham and computer gear before if s 
too old to sell. You know you're not going to use it again, so why leave rt for your 
widow to throw out? Thai stuff isn't getting any youngerl 

The 73 Rea Market, Barter n" Buy, costs you peanuts (almost)— comes to 35 cents 
a word for individual (noncommercial) ads and SI .00 a word for commercial ads. 
Don't plan on telling a k>ng story. Use abbreviations, cram it in. But be honest 
There are plenty of hams who love to fix things, so rf it doesn't work, say so. 
Make your list, count the woids, including your call, address and phone number. 
Include a check or your credit card number and expiration, if you're placing a com- 
mercial ad, include an additional phone number, separate from your ad. 
This is a monthly magazine, not a daily newspaper, so figure a couple months 
before the action starts; then be prepared. If you get too many calls, you priced it 
low. If you don't get many calls, too high. 

So get busy. Blow the dust off, check everything out, make sure it stilt works right 
and maybe you can help make a ham sure it still works right and maybe you can 
hetp make a ham newcomer or retired old timer happy with that rig you're not using 
now. Or you might get busy on your computer and put together a list of small gear/ 
parts to send to those interested? 



The deadline for the April 1997 classified ad section la February 12th, 1997. 



Large assortment of used test equip- 
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10% of original cost or less. Request 
list Jim Stevenson, 3401 Sunny 
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(908) 722-6157. Fax: (908) 722-6391. 

BNB2084 

RF TRANSISTORS TUBES 2SC2879. 
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ITS BACKI The return of the HW-6 
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BNB404 



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Convert Excess Equipment to CASH We buy good clean, used equipment Estate Sales 



86 73 Amateur Radio Today • February 1997 



Letters 

Continued from page 85 

local dealer has it for $3.49 for 12 

yaids t Anatk)nwrdcdi^bu!orisDick 
Blkk An Materials (800*723-2787); 
their item number is 606-3601, price 
$3.20 for 12 yards* plus shipping. 
Howe ver, be sum and get copper tape, 
not the lead tape some dealers also 
carry. The copper foil (tape) originally 
was intended to wrap the edges 
of "Tiffany" type stained glass 
ornaments and windows. 

OK, antenna weather is here— 
still winter, so I want to see a bunch 
of "Curses, Foiled Again * antenna 
construction articles.., Wayne. 

Craig Roberts WB5HKO/1. 
I've just read your wonderful edi- 
torial on entrepreneurship. Good 
job! A year ago 1 was an out-of- 
work advertising copywriter and 
ex-radio announcer feeling terribly 
sorry for myself; abused by society 
and victimized by a "bad 
economy." My pathetic mood was 
exacerbated by the necessity of sell- 
ing the contents of my modest shack 
in order to meet a mortgage pay- 
ment. My God t evil and over- 
whelming forces had forced my to 
give up not only my dignity as a 
family provider, but the trappings 
of my beloved hobby as well. 
Things couldn't be worse! Woe was 
me. Then, during one of many tele- 
phone calls to "Help Wanted" ad- 
vertisers I was put on hold. While 
in that telephonic limbo, 1 heard 
several minutes of informative pro- 
motional messages for the company 
I had called "Hmmm," I thought, 
"I could do that, f could write, pro- 
duce and sell telephone on-bold 
messages," The disciplines in- 
volved were well within my pro- 
fessional capabilities and the 
investment needed io get into die 
business was nearly zip, I excitedly 
fold a few friends about my plan and 
was met by doomsaying: "Start 
your own business in conservative 
old New England? You must be 
mad] The economy's terrible and 
no one will buy your radical ser- 
vice!" Having nothing belter to do, 
I persevered, I went door to door 
taking orders and small deposits, 
With the deposit money I rented 
some audio equipment and deliv- 
ered on my promises. It worked 
wonderfully, Mine isn't the largest 

on-hold company in the country, but 
Continued on page 87 



Number 87 on your Feedback card 



Proprghtion 



Jim Gray W1XU 
210 Chateau Circle 
Payson AZ 85541 

February is likely to be a rather 
"blah'* month (again) for DX 
propagation due to generally de- 
pressed seasonal and cyclical so- 
lar flux values, which have 
hovered in the high 60s and low 
70s for almost a year. However, 
it is expected that there will be fa- 
vorable increases in solar flux — 
hence DX propagation — during 

late summer and fall. 

On the brighter side, noise lev- 
els (QRN) should be fairly low 



this month, and few days are ex- 
pected to present any great storm 
activity in either atmosphere or 
ionosphere. You may want to try 
your DX ability on the 6th, 1 l- 
12th, and 21-22nd while avoid- 
ing the days surrounding the 3rd, 
17th and 27th. 

Listen often to WWV at 18 
minutes after any hour. The 10 
MHz frequency is best for me but 
you may wish to try 5, 15 or 20 
MHz for best reception at your 
QTH. Best "conditions" will ap- 
pear when the "A" and il K" in- 
dexes are low (Boulder K less 



EASTERN UNITED STATES TO: 



GMT: 


00 


02 


04 


06 


08 


10 


12 


14 


16 


10 


20 


22 


ALASKA 












20 


20 










ARGENTINA 


20 


40 


40 


40 


80 


80 








20 


15 


15 


AUSTRALIA 


20 




20 




40 


40 


20 


20 






15 


15 


CANAL ZONE 


15 


20 


20 


40 


40 




2D 


20 


15 


15 


15 


15 


ENGLAND 


20 


40 


80 


40 


40 




20 


20 


20 


20 


20 


20 


HAWAII 


20 




2D 




40 


40 


80 


20 






15 


15 


INDIA 


20 ! 










20 


40 


20 








15 


JAPAN 


20 












20 


20 








20 


MEXICO 


15 


20 


20 


40 


40 


^^^— 


20 


20 


15 


15 


15 


15 


PHILIPPINES 












20 












PUERTO RICO 


15 


20 


20 


40 


40 




20 


20 


15 


15 


15 


15 


SOUTH AFRICA 






40 


40 








15 


15 
20 


15 


20 


20 


US.S,FL 


40 


80 


80 


40 






20 


20 






40 


WEST COAST 




80 


80 


40 


40 


40 


SO 


20 


20 









CENTRAL UNITED STATES TO: 



ALASKA 



ARGENTINA 



AUSTRALIA 



CANAL ZONE 



ENGLAND 



HAWAII 



INDIA 



JAPAN 



MEXICO 



PHILIPPINES 



PUERTO RICO 



20 



20 



40 



15 



15 



20 



80 



40 



20 



20 



80 



20 



SOUTH AFRICA 



U.S.S.R 



20 



40 



80 



40 



40 



40 



40 



20 



40 



40 



40 



40 



40 



80 



40 



40 



40 



40 



40 



80 



40 



40 



40 



80 



40 



40 



40 



40 



40 



40 



20 



20 



40 



40 



40 



20 



20 



20 



20 



20 



20 



20 



20 



20 



20 



20 



20 



20 



15 



15 



20 



15 



20 



15 



15 



15 



20 



15 



15 
15 



15 



15 



15 



15 



15 



20 



WESTERN UNITED STATES TO: 



ALASKA 



ARGENTINA 



AUSTRALIA 



CANAL ZONE 



ENGLAND 



HAWAII 



INDIA 



JAPAN 



MEXICO 



PHILIPPINES 



PUERTO RICO 



SOUTH AFRICA 



US.S.R. 



EAST COAST 



15 



15 



15 



20 



15 



15 



20 



15 



20 



20 



20 



20 



20 



20 



15 



20 



20 



20 



20 



20 



40 



40 



80 



20 



80 



40 



40 



80 



40 



40 



40 



40 



40 



40 

40 



40 



40 



40 



20 



40 



40 



40 



40 



40 



40 40 



40 



40 



20 



40 



40 



40 



40 



40 



40 



20 



40 



80 



20 



40 40 



40 40 



20 



20 



40 



40 



20 



20 



40 



20 



20 



20 



20 



15 



15 



15 



20 



15 



20 



15 



15 



20 



15 



15 



15 



15 



15 



15 



15 



15 



20 



40 



15 



20 



20 



20 



20 



15 



15 



15 



15 



20 



J5. 

20 



15 



20 



FEBRUARY 1997 

SUN MON TUE WED THU FRI SAT 


- 












1 F 


2 F-P 


3 P 


4 P-F 


5 F-G 


6 G 


7G-F 


8 F 


9 F 


10F-G 


11 G 


12G 


13G-F 


14 F 


15 F 


16 F-P 


17 P 


18 P-F 


19 F 


20 F-G 


21 G 


22 G 


23 G 


24G-F 


25 F 


26 F-P 


27 P 


28 P-F 





than 3 and A less than 1 0) with 
accompanying solar flux values 
moving upward into the 80s and 
90s. 

Don't give up,,. better times are 
coming, and the skills you 
develop now will stand you in 
good stead when propagation 
improves. W1XU. 

10-12 meters 

A few possible daytime F2 
layer openings to South and Cen- 
tral America on the Good (G) 
days, 

15-17 meters 

Fair DX openings on Good (G) 
days between noon and sunset, 
and short-skip openings during 
the daylight hours. The band dies 
at sunset. 

20 meters 

DX to most areas of the world 
during daylight hours, peaking a 
few hours after sunrise and again 
during the early afternoon. Al- 
though the band usually closes 
soon after sunset, you may find 
occasional openings to South 
America and Antarctica until mid- 
night. Daylight short skip from 
several hundred to 2,000 miles or 
so possible on most Good (G) or 
Fair (F) days. 

30 meters 

DX toward Europe in the late 
afternoon and evening on Good 
(G) days until midnight, and then 
toward the Orient in the early sun- 
rise hours. Possible long-path DX 
in the morning and also short skip 
most days out to a thousand miles 
or more, and farther in the 
evening. 

73 Amateur 



40 meters 

DX toward Europe and Africa 
in laic afternoon hours, toward 
South and Central America 
around sunset, and good openings 
to the West and South Pacific 
peaking around sunrise on Good 
(G) days. Expect daytime short 
skip to 1 ,000 miles, and 2,000 
miles at night. 

80-1 60 meters 

Both are excellent bands for 
DX during hours of darkness, 
peaking at midnight and just be- 
fore dawn. Daytime skip on 160 
is nonexistent, but on 80 it can be 
up to 500 miles, and over 2,000 
miles at night. On 1 60, short skip 
can reach from 1 ,000-2,500 miles 
at night. Experts prefer vertical 
polarization for transmitting an- 
tennas (low-angle signal lake-off) 
and horizontal polarization for re- 
ceiving antennas (less noise) on 
160 meters. 



Letters 

Continued from page 86 
none offers better service or a su- 
perior product — and I've recendy 
expanded my business to provide 
custom newsletters and collateral 
marketing materials for small busi- 
nesses. I'm now totally self-suffi- 
cient and better off than ever 
financially, And my company's 
only a year old! The best is yet to 
come. As you so convincingly said: 
Yes! It can be done! On behalf of 
the many you will inspire — thanks! 
All ir takes is Motivation, Detei^ 
mination, and Perseverance and 
you can do just about anything. And 
I'd much prefer to hear something 
promotional than the crappy 
music most on-hoid services use.. 
Wayne. K? 

Radio Today * February 1997 87 



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Hum help 



Number 33 on your Feedback card 



We are happy to provide Ham Help free on a space-available basis. 
To make our job easier and to ensure thai your listing is correct, please 
type or print your request clearly, double-spaced, on a full 8-1/2" x 
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message is for the Ham Help Column. Please remember to acknowledge 
responses to your requests. Thank you for your cooperation. 



G. ARC./ ATTN: KG477 

PSC 1005 Box 73 
FPOAE 09593-0 173, 



--I 



Any Yaesu Hints? 

I have a Yaesu FT-51R-HP 
Dual Band Transceiver with high 
power battery pack, digital dis- 
play microphones and cigarette 
lighter adapters. The unit will not 
stay on high power but reverts to 
a lower power setting. How can I 
achieve the specified 5 watt out- 
put from this radio and how can I 
gel il to stay on the high output 
setting of 5 watts when it is se- 
lected? Yaesu has already fiddled 
with this unit and returned it to 
me but the problem still occurs. 
Please respond to George T. Plan 
NIUUN. P.O. Box 21, Guild NH 
03754. 

Pirates of the Caribbean 

The hams of Guantanamo 
Bay are in a quandary. Rusty 
Auxier KG4AU, President of 
the Guantanamo Bay ARC 
(KG4AN), writes; 

"We have about four hams here 
who are active on HF, and it is 
sometimes difficult to QSL due to 
the fact that our club call, 




NO, ITe MOT H\fiH-EM£R6Y EUECTBO-MA6W6T\C 
FlELD-5 IKITUE SHACIt— - \ JU^T FORGOT TO 
UUftTER THE <§*!!* 1t4H4£S / 

88 73 Amateur Radio Today * February 1997 



KG4AN. has been deleted from 
Callb&oks for the last few years. 
I just received my copy of Radio 
Amateur Caltbook on CD-ROM, 
and discovered my stateside call 
said QSL via KG4AN' but there 
was no address for KG4AN. Of 
course, people wishing to QSL 
can go through the bureau, but 
thai adds a lot of extra time. The 
QSL route for any KG4?? hams 
is as follows: 



By the way. there are several 
pirates out there using KG4 
caJlstgns. A few known ones are 
KG4AA ? KG4AB and KG4US. 
Here is a list of the active hams 
who are live on the island: 

KG4AU - Rusty Auxier 
KG4WD - Wayne Duncan 
KG4KD - Kim Duncan 
KG4CQ - Tom Mann 
KG4HE - Ray Magorno 

"We do have visiting hams here 
on a regular basis, most notably 
KG4GC. Bill Gallier. If there is 
any doubt about the validity of a 
call; you can write us at the above 
address, ATTN: KG4AU, or for 
those hams on-line, the E-mail 
address is Rustman@AOL. 
COM." 



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Even if you don't have a 10M rig, you can pick up very 
good used xmtrs & revrs for next to nothing. 
Receiving converters (shown above) available for 

various segments Of 6M r 2M, 220, and 432 MHz. 

Kits from S49, wired/tested units only $99. 

• Xmittfrtg converters (at 
left) for 2M, 432 MHz. 

• Kits only $89 vhf or 

$99 uhf. 

• Power amplifiers up to 
SOW output. 




* Buy at low, factory -direct net prices and save! 

* For complete info, call or write for free catalog. 

* Order by mail, fax, or phone < a -12 am. 1-6 pm eastern time). 

• Min, $5 S&H Charge far first pound plus add'l weight & insurance. 

- Use VISA, Mastercard, Discover, check, or UPS C.O.D. 



View Catalog on our Web site: 

www. hamtro n ics.com 



e-mail; jv@hamtronics.com 



Get more features for your dollar with our 

REP-200 REPEATER 



A microprocessor-controlled repeater with 
full autopatch and many versatile dtmf con- 
trol features at less than you might 
pay for a bare -bones repeater 
or controller alone? 




• WP-JDB B£PE«itft 



* kit still anty $1095 

* factory assembled stiff only $1295 

50-54, 143-174, 213-233, 420-475 MHz. (9Q2-92B MHz slightly higher.) 
FCC typo accepted for commercial service in- 150 & 450 MHz bands, 




Digital Voice Recorder Option. Allows message 

up to 20 sec to be remotely recorded off the air. Play- 
back at user request by DTMF command, or as a periodi- 
cal voice id, or bath, Great for making club announce- 
ments! „....„.. ;; _...._„., ;. Only $100, 

REP-200C Economy Repeater. Real-voice ID, no 
dtmf or autopatch, Kit only $795, w&t $1 195, 

REP*200N Repeater. Without controller 50 you can 
use your own. Kit only $695, w&t $995. 



You'll KICK Yourself 

If You Build a Repeater 

Without Checking Out Our Catalog First! 



Hamtronics has the world's 

JBOr tjJJ? most complete line of mod- 

M^^m^i tiles for making repeaters. In 

addition to exciters, pa's, and 
receivers, we offer the fol- 
lowing controllers. 

COR-3. Inexpensive, flexible COR module with timers, 
courtesy beep, audio mixer only $49/kit p $79 w/t 

CWID, Traditional diode matrix ID'er kit only $59 

CWJD-2, Eprom-controlled ID'er. ..only $54/kit, $79 wtt 

DVR-1. Record your own voice up to 20 sec For voice 
id r playing cl u b a n n ounceme nts . $ 5 9/k i t, $99 w/t 

COR -4. Complete COR and CWID afl on one board. ID 
in eprom. Low power CMOS. y only $99/kit P $149 w/t 

COR -6- COR with real-voice id. Low power CMOS, 
non-volatile memory kit only $99, w/t only $149 

COR-5. pP controller with autopatch, reverse ap. phone 
remote control, lots of DTMF control functions, all on one 
board, as used in REP-200 Repeater $379 wft 

AP-3. Repeater autopatch, reverse autopatch, phone 
line remote control. Use with TD-2 kit $89 

TD-2, Four-digit DTMF decoder/controller. Five latching 

■ff functions, toll call restrictor. kit $79 

TD-4. DTMF contra tier as above except one on-off func- 
tion and no toll call restrictor. Can also use for selective 
calling; mute speaker until someone pages you. .. kit $49 







LOW NOISE RECEIVER P REAM PS 



LHG-( ) G A A S PET PREAMPS 
STILL ONLY $59! 

* Make your friends sick with 
envy! Work stations they don't 
even know are there. 

* Install one at the antenna and 
overcome coax losses. 

* Available for 28-30, 46-56, 137-152, 152-172, 210-230, 
400-470, and 800-960 MHz bands. 

LNW-( ) ECONOMY PREAMPS 
ONLY $29 kit, $44 wi red/tested 

• Miniature MOSFET Preamp 

• Solder terminals allow easy 
connection inside radios. 

Available for 25-35, 35-55, 55-90, 90-120, 120-150, 
150-200, 200-270, and 400-500 MHz hands. 



Out Jim tegrl 



ronics, inc 

SS-D Moul Rd; Hilton NY 144SB-9535 
Phone 716-392-9430 (fax 9420) 




Connect to 






♦ ♦ 



A full range of cellular 
antennas is available: hole 
mount, magnetic mount, 
on-glass and base station. 







SKA 900 1/4 



I 






MICROCELL MAG 





SKA 901 C 



SGM 




46049 VOLTA MANTOVANA - MN - HAD (39) 376/801 5 1 5 - Fax 

NORTH AMERICA OFFICE: TORONTO - CANADA - TEL. [5 1 9] 650 9277 - 



139(376/801254 

Fax (519) 650 1779